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authorLinus Torvalds <torvalds@linux-foundation.org>2018-09-12 23:57:48 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2018-09-13 15:18:04 -1000
commit7a9cdebdcc17e426fb5287e4a82db1dfe86339b2 (patch)
treede9aa025a0d421ee3ae3d1973e63419fff8545e5 /mm/Kconfig
parent54eda9df17f3215b9ed16629ee71ea07413efdaf (diff)
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mm: get rid of vmacache_flush_all() entirely
Jann Horn points out that the vmacache_flush_all() function is not only potentially expensive, it's buggy too. It also happens to be entirely unnecessary, because the sequence number overflow case can be avoided by simply making the sequence number be 64-bit. That doesn't even grow the data structures in question, because the other adjacent fields are already 64-bit. So simplify the whole thing by just making the sequence number overflow case go away entirely, which gets rid of all the complications and makes the code faster too. Win-win. [ Oleg Nesterov points out that the VMACACHE_FULL_FLUSHES statistics also just goes away entirely with this ] Reported-by: Jann Horn <jannh@google.com> Suggested-by: Will Deacon <will.deacon@arm.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/Kconfig')
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