path: root/mm/Kconfig.debug
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authorVlastimil Babka <>2020-12-14 19:13:34 -0800
committerLinus Torvalds <>2020-12-15 12:13:46 -0800
commit8db26a3d47354ce7271a8cab03cd65b9d3d610b9 (patch)
treeb0b0beaa94ba6ac24d0acc9554cc564f9bd0aa98 /mm/Kconfig.debug
parent04013513cc84c401c7de9023ff3eda7863fc4add (diff)
mm, page_poison: use static key more efficiently
Commit 11c9c7edae06 ("mm/page_poison.c: replace bool variable with static key") changed page_poisoning_enabled() to a static key check. However, the function is not inlined, so each check still involves a function call with overhead not eliminated when page poisoning is disabled. Analogically to how debug_pagealloc is handled, this patch converts page_poisoning_enabled() back to boolean check, and introduces page_poisoning_enabled_static() for fast paths. Both functions are inlined. The function kernel_poison_pages() is also called unconditionally and does the static key check inside. Remove it from there and put it to callers. Also split it to two functions kernel_poison_pages() and kernel_unpoison_pages() instead of the confusing bool parameter. Also optimize the check that enables page poisoning instead of debug_pagealloc for architectures without proper debug_pagealloc support. Move the check to init_mem_debugging_and_hardening() to enable a single static key instead of having two static branches in page_poisoning_enabled_static(). Link: Signed-off-by: Vlastimil Babka <> Reviewed-by: David Hildenbrand <> Cc: Mike Rapoport <> Cc: Rafael J. Wysocki <> Cc: Alexander Potapenko <> Cc: Kees Cook <> Cc: Laura Abbott <> Cc: Mateusz Nosek <> Cc: Michal Hocko <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'mm/Kconfig.debug')
0 files changed, 0 insertions, 0 deletions