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2022-10-03mm/page_alloc: fix freeing static percpu memoryMiaohe Lin
The size of struct per_cpu_zonestat can be 0 on !SMP && !NUMA. In that case, zone->per_cpu_zonestats will always equal to boot_zonestats. But in zone_pcp_reset(), zone->per_cpu_zonestats is freed via free_percpu() directly without checking against boot_zonestats first. boot_zonestats will be released by free_percpu() unexpectedly. Link: https://lkml.kernel.org/r/20220916072257.9639-7-linmiaohe@huawei.com Fixes: 28f836b6777b ("mm/page_alloc: split per cpu page lists and zone stats") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc: add __init annotations to init_mem_debugging_and_hardening()Miaohe Lin
It's only called by mm_init(). Add __init annotations to it. Link: https://lkml.kernel.org/r/20220916072257.9639-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc: remove obsolete comment in zone_statistics()Miaohe Lin
Since commit 43c95bcc51e4 ("mm/page_alloc: reduce duration that IRQs are disabled for VM counters"), zone_statistics() is not called with interrupts disabled. Update the corresponding comment. Link: https://lkml.kernel.org/r/20220916072257.9639-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: remove obsolete macro NR_PCP_ORDER_MASK and NR_PCP_ORDER_WIDTHMiaohe Lin
Since commit 8b10b465d0e1 ("mm/page_alloc: free pages in a single pass during bulk free"), they're not used anymore. Remove them. Link: https://lkml.kernel.org/r/20220916072257.9639-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc: make zone_pcp_update() staticMiaohe Lin
Since commit b92ca18e8ca5 ("mm/page_alloc: disassociate the pcp->high from pcp->batch"), zone_pcp_update() is only used in mm/page_alloc.c. Move zone_pcp_update() up to avoid forward declaration and then make it static. No functional change intended. Link: https://lkml.kernel.org/r/20220916072257.9639-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc: ensure kswapd doesn't accidentally go to sleepMiaohe Lin
Patch series "A few cleanup patches for mm", v2. This series contains a few cleanup patches to remove the obsolete comments and functions, use helper macro to improve readability and so on. More details can be found in the respective changelogs. This patch (of 16): If ALLOC_KSWAPD is set, wake_all_kswapds() will be called to ensure kswapd doesn't accidentally go to sleep. But when reserve_flags is set, alloc_flags will be overwritten and ALLOC_KSWAPD is thus lost. Preserve the ALLOC_KSWAPD flag in alloc_flags to ensure kswapd won't go to sleep accidentally. Link: https://lkml.kernel.org/r/20220916072257.9639-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220916072257.9639-2-linmiaohe@huawei.com Fixes: 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03security: kmsan: fix interoperability with auto-initializationAlexander Potapenko
Heap and stack initialization is great, but not when we are trying uses of uninitialized memory. When the kernel is built with KMSAN, having kernel memory initialization enabled may introduce false negatives. We disable CONFIG_INIT_STACK_ALL_PATTERN and CONFIG_INIT_STACK_ALL_ZERO under CONFIG_KMSAN, making it impossible to auto-initialize stack variables in KMSAN builds. We also disable CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON to prevent accidental use of heap auto-initialization. We however still let the users enable heap auto-initialization at boot-time (by setting init_on_alloc=1 or init_on_free=1), in which case a warning is printed. Link: https://lkml.kernel.org/r/20220915150417.722975-31-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03init: kmsan: call KMSAN initialization routinesAlexander Potapenko
kmsan_init_shadow() scans the mappings created at boot time and creates metadata pages for those mappings. When the memblock allocator returns pages to pagealloc, we reserve 2/3 of those pages and use them as metadata for the remaining 1/3. Once KMSAN starts, every page allocated by pagealloc has its associated shadow and origin pages. kmsan_initialize() initializes the bookkeeping for init_task and enables KMSAN. Link: https://lkml.kernel.org/r/20220915150417.722975-18-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: kmsan: maintain KMSAN metadata for page operationsAlexander Potapenko
Insert KMSAN hooks that make the necessary bookkeeping changes: - poison page shadow and origins in alloc_pages()/free_page(); - clear page shadow and origins in clear_page(), copy_user_highpage(); - copy page metadata in copy_highpage(), wp_page_copy(); - handle vmap()/vunmap()/iounmap(); Link: https://lkml.kernel.org/r/20220915150417.722975-15-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc.c: document bulkfree_pcp_prepare() return valueAndrew Morton
Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: ke.wang <ke.wang@unisoc.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Zhaoyang Huang <huangzhaoyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_alloc.c: rename check_free_page() to free_page_is_bad()Andrew Morton
The name "check_free_page()" provides no information regarding its return value when the page is indeed found to be bad. Renaming it to "free_page_is_bad()" makes it clear that a `true' return value means the page was bad. And make it return a bool, not an int. [akpm@linux-foundation.org: don't use bool as int] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: ke.wang <ke.wang@unisoc.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Zhaoyang Huang <huangzhaoyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: add pageblock_aligned() macroKefeng Wang
Add pageblock_aligned() and use it to simplify code. Link: https://lkml.kernel.org/r/20220907060844.126891-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: reuse pageblock_start/end_pfn() macroKefeng Wang
Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h, then they could be used somewhere else, not only in compaction, also use ALIGN_DOWN() instead of round_down() to be pair with ALIGN(), which should be same for pageblock usage. Link: https://lkml.kernel.org/r/20220907060844.126891-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26mm: reduce noise in show_mem for lowmem allocationsMichal Hocko
While discussing early DMA pool pre-allocation failure with Christoph [1] I have realized that the allocation failure warning is rather noisy for constrained allocations like GFP_DMA{32}. Those zones are usually not populated on all nodes very often as their memory ranges are constrained. This is an attempt to reduce the ballast that doesn't provide any relevant information for those allocation failures investigation. Please note that I have only compile tested it (in my default config setup) and I am throwing it mostly to see what people think about it. [1] http://lkml.kernel.org/r/20220817060647.1032426-1-hch@lst.de [mhocko@suse.com: update] Link: https://lkml.kernel.org/r/Yw29bmJTIkKogTiW@dhcp22.suse.cz [mhocko@suse.com: fix build] [akpm@linux-foundation.org: fix it for mapletree] [akpm@linux-foundation.org: update it for Michal's update] [mhocko@suse.com: fix arch/powerpc/xmon/xmon.c] Link: https://lkml.kernel.org/r/Ywh3C4dKB9B93jIy@dhcp22.suse.cz [akpm@linux-foundation.org: fix arch/sparc/kernel/setup_32.c] Link: https://lkml.kernel.org/r/YwScVmVofIZkopkF@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton
2022-09-26mm: prevent page_frag_alloc() from corrupting the memoryMaurizio Lombardi
A number of drivers call page_frag_alloc() with a fragment's size > PAGE_SIZE. In low memory conditions, __page_frag_cache_refill() may fail the order 3 cache allocation and fall back to order 0; In this case, the cache will be smaller than the fragment, causing memory corruptions. Prevent this from happening by checking if the newly allocated cache is large enough for the fragment; if not, the allocation will fail and page_frag_alloc() will return NULL. Link: https://lkml.kernel.org/r/20220715125013.247085-1-mlombard@redhat.com Fixes: b63ae8ca096d ("mm/net: Rename and move page fragment handling from net/ to mm/") Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Cc: Chen Lin <chen45464546@163.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm: remove BUG_ON() in __isolate_free_page()Kefeng Wang
Drop unneed comment and blank, adjust the variable, and the most important is to delete BUG_ON(). The page passed is always buddy page into __isolate_free_page() from compaction, page_isolation and page_reporting, and the caller also check the return, BUG_ON() is a too drastic measure, remove it. Link: https://lkml.kernel.org/r/20220901015043.189276-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/page_alloc.c: delete a redundant parameter of rmqueue_pcplistzezuo
The gfp_flags parameter is not used in rmqueue_pcplist, so directly delete this parameter. Link: https://lkml.kernel.org/r/20220831013404.3360714-1-zuoze1@huawei.com Signed-off-by: zezuo <zuoze1@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm: fix null-ptr-deref in kswapd_is_running()Kefeng Wang
kswapd_run/stop() will set pgdat->kswapd to NULL, which could race with kswapd_is_running() in kcompactd(), kswapd_run/stop() kcompactd() kswapd_is_running() pgdat->kswapd // error or nomal ptr verify pgdat->kswapd // load non-NULL pgdat->kswapd pgdat->kswapd = NULL task_is_running(pgdat->kswapd) // Null pointer derefence KASAN reports the null-ptr-deref shown below, vmscan: Failed to start kswapd on node 0 ... BUG: KASAN: null-ptr-deref in kcompactd+0x440/0x504 Read of size 8 at addr 0000000000000024 by task kcompactd0/37 CPU: 0 PID: 37 Comm: kcompactd0 Kdump: loaded Tainted: G OE 5.10.60 #1 Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: dump_backtrace+0x0/0x394 show_stack+0x34/0x4c dump_stack+0x158/0x1e4 __kasan_report+0x138/0x140 kasan_report+0x44/0xdc __asan_load8+0x94/0xd0 kcompactd+0x440/0x504 kthread+0x1a4/0x1f0 ret_from_fork+0x10/0x18 At present kswapd/kcompactd_run() and kswapd/kcompactd_stop() are protected by mem_hotplug_begin/done(), but without kcompactd(). There is no need to involve memory hotplug lock in kcompactd(), so let's add a new mutex to protect pgdat->kswapd accesses. Also, because the kcompactd task will check the state of kswapd task, it's better to call kcompactd_stop() before kswapd_stop() to reduce lock conflicts. [akpm@linux-foundation.org: add comments] Link: https://lkml.kernel.org/r/20220827111959.186838-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11page_ext: introduce boot parameter 'early_page_ext'Li Zhe
In commit 2f1ee0913ce5 ("Revert "mm: use early_pfn_to_nid in page_ext_init""), we call page_ext_init() after page_alloc_init_late() to avoid some panic problem. It seems that we cannot track early page allocations in current kernel even if page structure has been initialized early. This patch introduces a new boot parameter 'early_page_ext' to resolve this problem. If we pass it to the kernel, page_ext_init() will be moved up and the feature 'deferred initialization of struct pages' will be disabled to initialize the page allocator early and prevent the panic problem above. It can help us to catch early page allocations. This is useful especially when we find that the free memory value is not the same right after different kernel booting. [akpm@linux-foundation.org: fix section issue by removing __meminitdata] Link: https://lkml.kernel.org/r/20220825102714.669-1-lizhe.67@bytedance.com Signed-off-by: Li Zhe <lizhe.67@bytedance.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm: kill find_min_pfn_with_active_regions()Kefeng Wang
find_min_pfn_with_active_regions() is only called from free_area_init(). Open-code the PHYS_PFN(memblock_start_of_DRAM()) into free_area_init(), and kill find_min_pfn_with_active_regions(). Link: https://lkml.kernel.org/r/20220815111017.39341-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/page_alloc: only search higher order when fallbackAbel Wu
It seems unnecessary to search pages with order < alloc_order in fallback allocation. This can currently happen with ALLOC_NOFRAGMENT and alloc_order > pageblock_order, so add a test to prevent it. [vbabka@suse.cz: changelog addition] Link: https://lkml.kernel.org/r/20220803025121.47018-1-wuyun.abel@bytedance.com Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11page_alloc: remove inactive initializationLi kunyu
The allocation address of the table pointer variable is first performed in the function, no initialization assignment is required, and no invalid pointer will appear. Link: https://lkml.kernel.org/r/20220803064118.3664-1-kunyu@nfschina.com Signed-off-by: Li kunyu <kunyu@nfschina.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/page_alloc: fix race condition between build_all_zonelists and page ↵Mel Gorman
allocation Patrick Daly reported the following problem; NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - before offline operation [0] - ZONE_MOVABLE [1] - ZONE_NORMAL [2] - NULL For a GFP_KERNEL allocation, alloc_pages_slowpath() will save the offset of ZONE_NORMAL in ac->preferred_zoneref. If a concurrent memory_offline operation removes the last page from ZONE_MOVABLE, build_all_zonelists() & build_zonerefs_node() will update node_zonelists as shown below. Only populated zones are added. NODE_DATA(nid)->node_zonelists[ZONELIST_FALLBACK] - after offline operation [0] - ZONE_NORMAL [1] - NULL [2] - NULL The race is simple -- page allocation could be in progress when a memory hot-remove operation triggers a zonelist rebuild that removes zones. The allocation request will still have a valid ac->preferred_zoneref that is now pointing to NULL and triggers an OOM kill. This problem probably always existed but may be slightly easier to trigger due to 6aa303defb74 ("mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator") which distinguishes between zones that are completely unpopulated versus zones that have valid pages not managed by the buddy allocator (e.g. reserved, memblock, ballooning etc). Memory hotplug had multiple stages with timing considerations around managed/present page updates, the zonelist rebuild and the zone span updates. As David Hildenbrand puts it memory offlining adjusts managed+present pages of the zone essentially in one go. If after the adjustments, the zone is no longer populated (present==0), we rebuild the zone lists. Once that's done, we try shrinking the zone (start+spanned pages) -- which results in zone_start_pfn == 0 if there are no more pages. That happens *after* rebuilding the zonelists via remove_pfn_range_from_zone(). The only requirement to fix the race is that a page allocation request identifies when a zonelist rebuild has happened since the allocation request started and no page has yet been allocated. Use a seqlock_t to track zonelist updates with a lockless read-side of the zonelist and protecting the rebuild and update of the counter with a spinlock. [akpm@linux-foundation.org: make zonelist_update_seq static] Link: https://lkml.kernel.org/r/20220824110900.vh674ltxmzb3proq@techsingularity.net Fixes: 6aa303defb74 ("mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Patrick Daly <quic_pdaly@quicinc.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: <stable@vger.kernel.org> [4.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-24mm: add NR_SECONDARY_PAGETABLE to count secondary page table uses.Yosry Ahmed
We keep track of several kernel memory stats (total kernel memory, page tables, stack, vmalloc, etc) on multiple levels (global, per-node, per-memcg, etc). These stats give insights to users to how much memory is used by the kernel and for what purposes. Currently, memory used by KVM mmu is not accounted in any of those kernel memory stats. This patch series accounts the memory pages used by KVM for page tables in those stats in a new NR_SECONDARY_PAGETABLE stat. This stat can be later extended to account for other types of secondary pages tables (e.g. iommu page tables). KVM has a decent number of large allocations that aren't for page tables, but for most of them, the number/size of those allocations scales linearly with either the number of vCPUs or the amount of memory assigned to the VM. KVM's secondary page table allocations do not scale linearly, especially when nested virtualization is in use. From a KVM perspective, NR_SECONDARY_PAGETABLE will scale with KVM's per-VM pages_{4k,2m,1g} stats unless the guest is doing something bizarre (e.g. accessing only 4kb chunks of 2mb pages so that KVM is forced to allocate a large number of page tables even though the guest isn't accessing that much memory). However, someone would need to either understand how KVM works to make that connection, or know (or be told) to go look at KVM's stats if they're running VMs to better decipher the stats. Furthermore, having NR_PAGETABLE side-by-side with NR_SECONDARY_PAGETABLE is informative. For example, when backing a VM with THP vs. HugeTLB, NR_SECONDARY_PAGETABLE is roughly the same, but NR_PAGETABLE is an order of magnitude higher with THP. So having this stat will at the very least prove to be useful for understanding tradeoffs between VM backing types, and likely even steer folks towards potential optimizations. The original discussion with more details about the rationale: https://lore.kernel.org/all/87ilqoi77b.wl-maz@kernel.org This stat will be used by subsequent patches to count KVM mmu memory usage. Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20220823004639.2387269-2-yosryahmed@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-08-03Merge tag 'efi-next-for-v5.20' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi Pull EFI updates from Ard Biesheuvel: - Enable mirrored memory for arm64 - Fix up several abuses of the efivar API - Refactor the efivar API in preparation for moving the 'business logic' part of it into efivarfs - Enable ACPI PRM on arm64 * tag 'efi-next-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) ACPI: Move PRM config option under the main ACPI config ACPI: Enable Platform Runtime Mechanism(PRM) support on ARM64 ACPI: PRM: Change handler_addr type to void pointer efi: Simplify arch_efi_call_virt() macro drivers: fix typo in firmware/efi/memmap.c efi: vars: Drop __efivar_entry_iter() helper which is no longer used efi: vars: Use locking version to iterate over efivars linked lists efi: pstore: Omit efivars caching EFI varstore access layer efi: vars: Add thin wrapper around EFI get/set variable interface efi: vars: Don't drop lock in the middle of efivar_init() pstore: Add priv field to pstore_record for backend specific use Input: applespi - avoid efivars API and invoke EFI services directly selftests/kexec: remove broken EFI_VARS secure boot fallback check brcmfmac: Switch to appropriate helper to load EFI variable contents iwlwifi: Switch to proper EFI variable store interface media: atomisp_gmin_platform: stop abusing efivar API efi: efibc: avoid efivar API for setting variables efi: avoid efivars layer when loading SSDTs from variables efi: Correct comment on efi_memmap_alloc memblock: Disable mirror feature if kernelcore is not specified ...
2022-08-01Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "Highlights include a major rework of our kPTI page-table rewriting code (which makes it both more maintainable and considerably faster in the cases where it is required) as well as significant changes to our early boot code to reduce the need for data cache maintenance and greatly simplify the KASLR relocation dance. Summary: - Remove unused generic cpuidle support (replaced by PSCI version) - Fix documentation describing the kernel virtual address space - Handling of some new CPU errata in Arm implementations - Rework of our exception table code in preparation for handling machine checks (i.e. RAS errors) more gracefully - Switch over to the generic implementation of ioremap() - Fix lockdep tracking in NMI context - Instrument our memory barrier macros for KCSAN - Rework of the kPTI G->nG page-table repainting so that the MMU remains enabled and the boot time is no longer slowed to a crawl for systems which require the late remapping - Enable support for direct swapping of 2MiB transparent huge-pages on systems without MTE - Fix handling of MTE tags with allocating new pages with HW KASAN - Expose the SMIDR register to userspace via sysfs - Continued rework of the stack unwinder, particularly improving the behaviour under KASAN - More repainting of our system register definitions to match the architectural terminology - Improvements to the layout of the vDSO objects - Support for allocating additional bits of HWCAP2 and exposing FEAT_EBF16 to userspace on CPUs that support it - Considerable rework and optimisation of our early boot code to reduce the need for cache maintenance and avoid jumping in and out of the kernel when handling relocation under KASLR - Support for disabling SVE and SME support on the kernel command-line - Support for the Hisilicon HNS3 PMU - Miscellanous cleanups, trivial updates and minor fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (136 commits) arm64: Delay initialisation of cpuinfo_arm64::reg_{zcr,smcr} arm64: fix KASAN_INLINE arm64/hwcap: Support FEAT_EBF16 arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long arm64/hwcap: Document allocation of upper bits of AT_HWCAP arm64: enable THP_SWAP for arm64 arm64/mm: use GENMASK_ULL for TTBR_BADDR_MASK_52 arm64: errata: Remove AES hwcap for COMPAT tasks arm64: numa: Don't check node against MAX_NUMNODES drivers/perf: arm_spe: Fix consistency of SYS_PMSCR_EL1.CX perf: RISC-V: Add of_node_put() when breaking out of for_each_of_cpu_node() docs: perf: Include hns3-pmu.rst in toctree to fix 'htmldocs' WARNING arm64: kasan: Revert "arm64: mte: reset the page tag in page->flags" mm: kasan: Skip page unpoisoning only if __GFP_SKIP_KASAN_UNPOISON mm: kasan: Skip unpoisoning of user pages mm: kasan: Ensure the tags are visible before the tag in page->flags drivers/perf: hisi: add driver for HNS3 PMU drivers/perf: hisi: Add description for HNS3 PMU driver drivers/perf: riscv_pmu_sbi: perf format perf/arm-cci: Use the bitmap API to allocate bitmaps ...
2022-07-29mm/page_alloc: correct the wrong cpuset file path in commentMark-PK Tsai
cpuset.c was moved to kernel/cgroup/ in below commit 201af4c0fab0 ("cgroup: move cgroup files under kernel/cgroup/") Correct the wrong path in comment. Link: https://lkml.kernel.org/r/20220718120336.5145-1-mark-pk.tsai@mediatek.com Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29page_alloc: fix invalid watermark check on a negative valueJaewon Kim
There was a report that a task is waiting at the throttle_direct_reclaim. The pgscan_direct_throttle in vmstat was increasing. This is a bug where zone_watermark_fast returns true even when the free is very low. The commit f27ce0e14088 ("page_alloc: consider highatomic reserve in watermark fast") changed the watermark fast to consider highatomic reserve. But it did not handle a negative value case which can be happened when reserved_highatomic pageblock is bigger than the actual free. If watermark is considered as ok for the negative value, allocating contexts for order-0 will consume all free pages without direct reclaim, and finally free page may become depleted except highatomic free. Then allocating contexts may fall into throttle_direct_reclaim. This symptom may easily happen in a system where wmark min is low and other reclaimers like kswapd does not make free pages quickly. Handle the negative case by using MIN. Link: https://lkml.kernel.org/r/20220725095212.25388-1-jaewon31.kim@samsung.com Fixes: f27ce0e14088 ("page_alloc: consider highatomic reserve in watermark fast") Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Reported-by: GyeongHwan Hong <gh21.hong@samsung.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Yong-Taek Lee <ytk.lee@samsung.com> Cc: <stable@vger.kerenl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: use try_cmpxchg in set_pfnblock_flags_maskUros Bizjak
Use try_cmpxchg instead of cmpxchg in set_pfnblock_flags_mask. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). The main loop improves from: 1c5d: 48 89 c2 mov %rax,%rdx 1c60: 48 89 c1 mov %rax,%rcx 1c63: 48 21 fa and %rdi,%rdx 1c66: 4c 09 c2 or %r8,%rdx 1c69: f0 48 0f b1 16 lock cmpxchg %rdx,(%rsi) 1c6e: 48 39 c1 cmp %rax,%rcx 1c71: 75 ea jne 1c5d <...> to: 1c60: 48 89 ca mov %rcx,%rdx 1c63: 48 21 c2 and %rax,%rdx 1c66: 4c 09 c2 or %r8,%rdx 1c69: f0 48 0f b1 16 lock cmpxchg %rdx,(%rsi) 1c6e: 75 f0 jne 1c60 <...> Link: https://lkml.kernel.org/r/20220708140736.8737-1-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm, hugetlb: skip irrelevant nodes in show_free_areas()Gang Li
show_free_areas() allows to filter out node specific data which is irrelevant to the allocation request. But hugetlb_show_meminfo() still shows hugetlb on all nodes, which is redundant and unnecessary. Use show_mem_node_skip() to skip irrelevant nodes. And replace hugetlb_show_meminfo() with hugetlb_show_meminfo_node(nid). before-and-after sample output of OOM: before: ``` [ 214.362453] Node 1 active_anon:148kB inactive_anon:4050920kB active_file:112kB inactive_file:100kB [ 214.375429] Node 1 Normal free:45100kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig [ 214.388334] lowmem_reserve[]: 0 0 0 0 0 [ 214.390251] Node 1 Normal: 423*4kB (UE) 320*8kB (UME) 187*16kB (UE) 117*32kB (UE) 57*64kB (UME) 20 [ 214.397626] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [ 214.401518] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB ``` after: ``` [ 145.069705] Node 1 active_anon:128kB inactive_anon:4049412kB active_file:56kB inactive_file:84kB u [ 145.110319] Node 1 Normal free:45424kB boost:0kB min:45576kB low:56968kB high:68360kB reserved_hig [ 145.152315] lowmem_reserve[]: 0 0 0 0 0 [ 145.155244] Node 1 Normal: 470*4kB (UME) 373*8kB (UME) 247*16kB (UME) 168*32kB (UE) 86*64kB (UME) [ 145.164119] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB ``` Link: https://lkml.kernel.org/r/20220706034655.1834-1-ligang.bdlg@bytedance.com Signed-off-by: Gang Li <ligang.bdlg@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: replace local_lock with normal spinlockMel Gorman
struct per_cpu_pages is no longer strictly local as PCP lists can be drained remotely using a lock for protection. While the use of local_lock works, it goes against the intent of local_lock which is for "pure CPU local concurrency control mechanisms and not suited for inter-CPU concurrency control" (Documentation/locking/locktypes.rst) local_lock protects against migration between when the percpu pointer is accessed and the pcp->lock acquired. The lock acquisition is a preemption point so in the worst case, a task could migrate to another NUMA node and accidentally allocate remote memory. The main requirement is to pin the task to a CPU that is suitable for PREEMPT_RT and !PREEMPT_RT. Replace local_lock with helpers that pin a task to a CPU, lookup the per-cpu structure and acquire the embedded lock. It's similar to local_lock without breaking the intent behind the API. It is not a complete API as only the parts needed for PCP-alloc are implemented but in theory, the generic helpers could be promoted to a general API if there was demand for an embedded lock within a per-cpu struct with a guarantee that the per-cpu structure locked matches the running CPU and cannot use get_cpu_var due to RT concerns. PCP requires these semantics to avoid accidentally allocating remote memory. [mgorman@techsingularity.net: use pcp_spin_trylock_irqsave instead of pcpu_spin_trylock_irqsave] Link: https://lkml.kernel.org/r/20220627084645.GA27531@techsingularity.net Link: https://lkml.kernel.org/r/20220624125423.6126-8-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: remotely drain per-cpu listsNicolas Saenz Julienne
Some setups, notably NOHZ_FULL CPUs, are too busy to handle the per-cpu drain work queued by __drain_all_pages(). So introduce a new mechanism to remotely drain the per-cpu lists. It is made possible by remotely locking 'struct per_cpu_pages' new per-cpu spinlocks. A benefit of this new scheme is that drain operations are now migration safe. There was no observed performance degradation vs. the previous scheme. Both netperf and hackbench were run in parallel to triggering the __drain_all_pages(NULL, true) code path around ~100 times per second. The new scheme performs a bit better (~5%), although the important point here is there are no performance regressions vs. the previous mechanism. Per-cpu lists draining happens only in slow paths. Minchan Kim tested an earlier version and reported; My workload is not NOHZ CPUs but run apps under heavy memory pressure so they goes to direct reclaim and be stuck on drain_all_pages until work on workqueue run. unit: nanosecond max(dur) avg(dur) count(dur) 166713013 487511.77786438033 1283 From traces, system encountered the drain_all_pages 1283 times and worst case was 166ms and avg was 487us. The other problem was alloc_contig_range in CMA. The PCP draining takes several hundred millisecond sometimes though there is no memory pressure or a few of pages to be migrated out but CPU were fully booked. Your patch perfectly removed those wasted time. Link: https://lkml.kernel.org/r/20220624125423.6126-7-mgorman@techsingularity.net Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Yu Zhao <yuzhao@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: protect PCP lists with a spinlockMel Gorman
Currently the PCP lists are protected by using local_lock_irqsave to prevent migration and IRQ reentrancy but this is inconvenient. Remote draining of the lists is impossible and a workqueue is required and every task allocation/free must disable then enable interrupts which is expensive. As preparation for dealing with both of those problems, protect the lists with a spinlock. The IRQ-unsafe version of the lock is used because IRQs are already disabled by local_lock_irqsave. spin_trylock is used in combination with local_lock_irqsave() but later will be replaced with a spin_trylock_irqsave when the local_lock is removed. The per_cpu_pages still fits within the same number of cache lines after this patch relative to before the series. struct per_cpu_pages { spinlock_t lock; /* 0 4 */ int count; /* 4 4 */ int high; /* 8 4 */ int batch; /* 12 4 */ short int free_factor; /* 16 2 */ short int expire; /* 18 2 */ /* XXX 4 bytes hole, try to pack */ struct list_head lists[13]; /* 24 208 */ /* size: 256, cachelines: 4, members: 7 */ /* sum members: 228, holes: 1, sum holes: 4 */ /* padding: 24 */ } __attribute__((__aligned__(64))); There is overhead in the fast path due to acquiring the spinlock even though the spinlock is per-cpu and uncontended in the common case. Page Fault Test (PFT) running on a 1-socket reported the following results on a 1 socket machine. 5.19.0-rc3 5.19.0-rc3 vanilla mm-pcpspinirq-v5r16 Hmean faults/sec-1 869275.7381 ( 0.00%) 874597.5167 * 0.61%* Hmean faults/sec-3 2370266.6681 ( 0.00%) 2379802.0362 * 0.40%* Hmean faults/sec-5 2701099.7019 ( 0.00%) 2664889.7003 * -1.34%* Hmean faults/sec-7 3517170.9157 ( 0.00%) 3491122.8242 * -0.74%* Hmean faults/sec-8 3965729.6187 ( 0.00%) 3939727.0243 * -0.66%* There is a small hit in the number of faults per second but given that the results are more stable, it's borderline noise. [akpm@linux-foundation.org: add missing local_unlock_irqrestore() on contention path] Link: https://lkml.kernel.org/r/20220624125423.6126-6-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: remove mistaken page == NULL check in rmqueueMel Gorman
If a page allocation fails, the ZONE_BOOSTER_WATERMARK should be tested, cleared and kswapd woken whether the allocation attempt was via the PCP or directly via the buddy list. Remove the page == NULL so the ZONE_BOOSTED_WATERMARK bit is checked unconditionally. As it is unlikely that ZONE_BOOSTED_WATERMARK is set, mark the branch accordingly. Link: https://lkml.kernel.org/r/20220624125423.6126-5-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nicolas Saenz Julienne <nsaenzju@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: split out buddy removal code from rmqueue into separate helperMel Gorman
This is a preparation page to allow the buddy removal code to be reused in a later patch. No functional change. Link: https://lkml.kernel.org/r/20220624125423.6126-4-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: use only one PCP list for THP-sized allocationsMel Gorman
The per_cpu_pages is cache-aligned on a standard x86-64 distribution configuration but a later patch will add a new field which would push the structure into the next cache line. Use only one list to store THP-sized pages on the per-cpu list. This assumes that the vast majority of THP-sized allocations are GFP_MOVABLE but even if it was another type, it would not contribute to serious fragmentation that potentially causes a later THP allocation failure. Align per_cpu_pages on the cacheline boundary to ensure there is no false cache sharing. After this patch, the structure sizing is; struct per_cpu_pages { int count; /* 0 4 */ int high; /* 4 4 */ int batch; /* 8 4 */ short int free_factor; /* 12 2 */ short int expire; /* 14 2 */ struct list_head lists[13]; /* 16 208 */ /* size: 256, cachelines: 4, members: 6 */ /* padding: 32 */ } __attribute__((__aligned__(64))); Link: https://lkml.kernel.org/r/20220624125423.6126-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nicolas Saenz Julienne <nsaenzju@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17mm/page_alloc: add page->buddy_list and page->pcp_listMel Gorman
Patch series "Drain remote per-cpu directly", v5. Some setups, notably NOHZ_FULL CPUs, may be running realtime or latency-sensitive applications that cannot tolerate interference due to per-cpu drain work queued by __drain_all_pages(). Introduce a new mechanism to remotely drain the per-cpu lists. It is made possible by remotely locking 'struct per_cpu_pages' new per-cpu spinlocks. This has two advantages, the time to drain is more predictable and other unrelated tasks are not interrupted. This series has the same intent as Nicolas' series "mm/page_alloc: Remote per-cpu lists drain support" -- avoid interference of a high priority task due to a workqueue item draining per-cpu page lists. While many workloads can tolerate a brief interruption, it may cause a real-time task running on a NOHZ_FULL CPU to miss a deadline and at minimum, the draining is non-deterministic. Currently an IRQ-safe local_lock protects the page allocator per-cpu lists. The local_lock on its own prevents migration and the IRQ disabling protects from corruption due to an interrupt arriving while a page allocation is in progress. This series adjusts the locking. A spinlock is added to struct per_cpu_pages to protect the list contents while local_lock_irq is ultimately replaced by just the spinlock in the final patch. This allows a remote CPU to safely. Follow-on work should allow the spin_lock_irqsave to be converted to spin_lock to avoid IRQs being disabled/enabled in most cases. The follow-on patch will be one kernel release later as it is relatively high risk and it'll make bisections more clear if there are any problems. Patch 1 is a cosmetic patch to clarify when page->lru is storing buddy pages and when it is storing per-cpu pages. Patch 2 shrinks per_cpu_pages to make room for a spin lock. Strictly speaking this is not necessary but it avoids per_cpu_pages consuming another cache line. Patch 3 is a preparation patch to avoid code duplication. Patch 4 is a minor correction. Patch 5 uses a spin_lock to protect the per_cpu_pages contents while still relying on local_lock to prevent migration, stabilise the pcp lookup and prevent IRQ reentrancy. Patch 6 remote drains per-cpu pages directly instead of using a workqueue. Patch 7 uses a normal spinlock instead of local_lock for remote draining This patch (of 7): The page allocator uses page->lru for storing pages on either buddy or PCP lists. Create page->buddy_list and page->pcp_list as a union with page->lru. This is simply to clarify what type of list a page is on in the page allocator. No functional change intended. [minchan@kernel.org: fix page lru fields in macros] Link: https://lkml.kernel.org/r/20220624125423.6126-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-07mm: kasan: Skip page unpoisoning only if __GFP_SKIP_KASAN_UNPOISONCatalin Marinas
Currently post_alloc_hook() skips the kasan unpoisoning if the tags will be zeroed (__GFP_ZEROTAGS) or __GFP_SKIP_KASAN_UNPOISON is passed. Since __GFP_ZEROTAGS is now accompanied by __GFP_SKIP_KASAN_UNPOISON, remove the extra check. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20220610152141.2148929-4-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2022-07-07mm: kasan: Skip unpoisoning of user pagesCatalin Marinas
Commit c275c5c6d50a ("kasan: disable freed user page poisoning with HW tags") added __GFP_SKIP_KASAN_POISON to GFP_HIGHUSER_MOVABLE. A similar argument can be made about unpoisoning, so also add __GFP_SKIP_KASAN_UNPOISON to user pages. To ensure the user page is still accessible via page_address() without a kasan fault, reset the page->flags tag. With the above changes, there is no need for the arm64 tag_clear_highpage() to reset the page->flags tag. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20220610152141.2148929-3-catalin.marinas@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2022-07-03mm/page_alloc: make the annotations of available memory more accurateYang Yang
Not all systems use swap, so estimating available memory would help to prevent swapping or OOM of system that not use swap. And we need to reserve some page cache to prevent swapping or thrashing. If somebody is accessing the pages in pagecache, and if too much would be freed, most accesses might mean reading data from disk, i.e. thrashing. Link: https://lkml.kernel.org/r/20220623020833.972979-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: CGEL ZTE <cgel.zte@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm: convert destroy_compound_page() to destroy_large_folio()Matthew Wilcox (Oracle)
All callers now have a folio, so push the folio->page conversion down to this function. [akpm@linux-foundation.org: uninline destroy_large_folio() to fix build issue] Link: https://lkml.kernel.org/r/20220617175020.717127-20-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm: introduce clear_highpage_kasan_taggedAndrey Konovalov
Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a page potentially tagged by KASAN. This helper is used by the following patch. Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03mm: rename kernel_init_free_pages to kernel_init_pagesAndrey Konovalov
Rename kernel_init_free_pages() to kernel_init_pages(). This function is not only used for free pages but also for pages that were just allocated. Link: https://lkml.kernel.org/r/1ecaffc0a9c1404d4d7cf52efe0b2dc8a0c681d8.1654798516.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16mm/page_alloc: use might_alloc()Daniel Vetter
... instead of open coding it. Completely equivalent code, just a notch more meaningful when reading. Link: https://lkml.kernel.org/r/20220605152539.3196045-1-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-15memblock: Disable mirror feature if kernelcore is not specifiedMa Wupeng
If system have some mirrored memory and mirrored feature is not specified in boot parameter, the basic mirrored feature will be enabled and this will lead to the following situations: - memblock memory allocation prefers mirrored region. This may have some unexpected influence on numa affinity. - contiguous memory will be split into several parts if parts of them is mirrored memory via memblock_mark_mirror(). To fix this, variable mirrored_kernelcore will be checked in memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff kernelcore=mirror is added in the kernel parameters. Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20220614092156.1972846-6-mawupeng1@huawei.com Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2022-05-27Merge tag 'mm-stable-2022-05-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more MM updates from Andrew Morton: - Two follow-on fixes for the post-5.19 series "Use pageblock_order for cma and alloc_contig_range alignment", from Zi Yan. - A series of z3fold cleanups and fixes from Miaohe Lin. - Some memcg selftests work from Michal Koutný <mkoutny@suse.com> - Some swap fixes and cleanups from Miaohe Lin - Several individual minor fixups * tag 'mm-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (25 commits) mm/shmem.c: suppress shift warning mm: Kconfig: reorganize misplaced mm options mm: kasan: fix input of vmalloc_to_page() mm: fix is_pinnable_page against a cma page mm: filter out swapin error entry in shmem mapping mm/shmem: fix infinite loop when swap in shmem error at swapoff time mm/madvise: free hwpoison and swapin error entry in madvise_free_pte_range mm/swapfile: fix lost swap bits in unuse_pte() mm/swapfile: unuse_pte can map random data if swap read fails selftests: memcg: factor out common parts of memory.{low,min} tests selftests: memcg: remove protection from top level memcg selftests: memcg: adjust expected reclaim values of protected cgroups selftests: memcg: expect no low events in unprotected sibling selftests: memcg: fix compilation mm/z3fold: fix z3fold_page_migrate races with z3fold_map mm/z3fold: fix z3fold_reclaim_page races with z3fold_free mm/z3fold: always clear PAGE_CLAIMED under z3fold page lock mm/z3fold: put z3fold page back into unbuddied list when reclaim or migration fails revert "mm/z3fold.c: allow __GFP_HIGHMEM in z3fold_alloc" mm/z3fold: throw warning on failure of trylock_page in z3fold_alloc ...
2022-05-27Merge tag 'mm-hotfixes-stable-2022-05-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "Six hotfixes. The page_table_check one from Miaohe Lin is considered a minor thing so it isn't marked for -stable. The remainder address pre-5.19 issues and are cc:stable" * tag 'mm-hotfixes-stable-2022-05-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/page_table_check: fix accessing unmapped ptep kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add] mm/page_alloc: always attempt to allocate at least one page during bulk allocation hugetlb: fix huge_pmd_unshare address update zsmalloc: fix races between asynchronous zspage free and page migration Revert "mm/cma.c: remove redundant cma_mutex lock"
2022-05-27mm: fix is_pinnable_page against a cma pageMinchan Kim
Pages in the CMA area could have MIGRATE_ISOLATE as well as MIGRATE_CMA so the current is_pinnable_page() could miss CMA pages which have MIGRATE_ISOLATE. It ends up pinning CMA pages as longterm for the pin_user_pages() API so CMA allocations keep failing until the pin is released. CPU 0 CPU 1 - Task B cma_alloc alloc_contig_range pin_user_pages_fast(FOLL_LONGTERM) change pageblock as MIGRATE_ISOLATE internal_get_user_pages_fast lockless_pages_from_mm gup_pte_range try_grab_folio is_pinnable_page return true; So, pinned the page successfully. page migration failure with pinned page .. .. After 30 sec unpin_user_page(page) CMA allocation succeeded after 30 sec. The CMA allocation path protects the migration type change race using zone->lock but what GUP path need to know is just whether the page is on CMA area or not rather than exact migration type. Thus, we don't need zone->lock but just checks migration type in either of (MIGRATE_ISOLATE and MIGRATE_CMA). Adding the MIGRATE_ISOLATE check in is_pinnable_page could cause rejecting of pinning pages on MIGRATE_ISOLATE pageblocks even though it's neither CMA nor movable zone if the page is temporarily unmovable. However, such a migration failure by unexpected temporal refcount holding is general issue, not only come from MIGRATE_ISOLATE and the MIGRATE_ISOLATE is also transient state like other temporal elevated refcount problem. Link: https://lkml.kernel.org/r/20220524171525.976723-1-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>