diff options
| author | David Hildenbrand <david@redhat.com> | 2021-03-23 11:01:10 +0100 |
|---|---|---|
| committer | Simon Horman <horms@verge.net.au> | 2021-04-02 12:05:57 +0200 |
| commit | 1bc7bc7649fa29d95c98f6a6d8dd2f08734a865c (patch) | |
| tree | ce454311c04daa62a7188237c2f40b4bc548e112 | |
| parent | 77ff3d6f49e87d071ac27dc49d2ca5a07c9fba6c (diff) | |
crashdump/x86: increase CRASH_MAX_MEMORY_RANGES to 32k
virtio-mem in Linux adds/removes individual memory blocks (e.g., 128 MB
each). Linux merges adjacent memory blocks added by virtio-mem devices, but
we can still end up with a very sparse memory layout when unplugging
memory in corner cases.
Let's increase the maximum number of crash memory ranges from ~2k to 32k.
32k should be sufficient for a very long time.
e_phnum field in the header is 16 bits wide, so we can fit a maximum of
~64k entries in there, shared with other entries (i.e., CPU). Therefore,
using up to 32k memory ranges is fine. (if we ever need more than ~64k,
we can switch to the sh_info field)
Move the temporary xen ranges off the stack, dynamically allocating
memory for them.
Note: We don't have to increase MAX_MEMORY_RANGES, because virtio-mem
added memory is driver managed and always detected and added by a
driver in the kexec'ed kernel; for ordinary kexec, we must not expose
these ranges in the firmware-provided memmap.
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
| -rw-r--r-- | kexec/arch/i386/crashdump-x86.c | 6 | ||||
| -rw-r--r-- | kexec/arch/i386/crashdump-x86.h | 3 |
2 files changed, 6 insertions, 3 deletions
diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c index 43e830a..df84185 100644 --- a/kexec/arch/i386/crashdump-x86.c +++ b/kexec/arch/i386/crashdump-x86.c @@ -355,8 +355,8 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges, static int get_crash_memory_ranges_xen(struct memory_range **range, int *ranges, unsigned long lowmem_limit) { + struct e820entry *e820entries; int j, rc, ret = -1; - struct e820entry e820entries[CRASH_MAX_MEMORY_RANGES]; unsigned int i; xc_interface *xc; @@ -367,6 +367,8 @@ static int get_crash_memory_ranges_xen(struct memory_range **range, return -1; } + e820entries = xmalloc(sizeof(*e820entries) * CRASH_MAX_MEMORY_RANGES); + rc = xc_get_machine_memory_map(xc, e820entries, CRASH_MAX_MEMORY_RANGES); if (rc < 0) { @@ -395,7 +397,7 @@ static int get_crash_memory_ranges_xen(struct memory_range **range, err: xc_interface_close(xc); - + free(e820entries); return ret; } #else diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h index e4fdc82..479a549 100644 --- a/kexec/arch/i386/crashdump-x86.h +++ b/kexec/arch/i386/crashdump-x86.h @@ -22,7 +22,8 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline, #define X86_64_KERNEL_TEXT_SIZE (512UL*1024*1024) #define CRASH_MAX_MEMMAP_NR 1024 -#define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2) + +#define CRASH_MAX_MEMORY_RANGES 32768 /* Backup Region, First 640K of System RAM. */ #define BACKUP_SRC_START 0x00000000 |