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charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Oct 19, 2020 at 8:31 PM Michal Hocko wrote: > > On Mon 19-10-20 18:15:20, Muchun Song wrote: > > For the exclusive reference page, the non-atomic operations is enough, > > so replace them to non-atomic operations. > > I do expect you do not see any difference in runtime and this is mostly > driven by the code reading, right? Being explicit about this in the code > would be preferred. Yeah, just code reading.And the set_bit and __set_bit is actually different on some architectures. Thanks. > > No objection to the change. > > > Signed-off-by: Muchun Song > > With an improved changelog > Acked-by: Michal Hocko > > > --- > > include/linux/page-flags.h | 2 ++ > > mm/memory.c | 4 ++-- > > 2 files changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > > index fbbb841a9346..ec039dde5e4b 100644 > > --- a/include/linux/page-flags.h > > +++ b/include/linux/page-flags.h > > @@ -401,6 +401,8 @@ static __always_inline int PageSwapCache(struct page *page) > > } > > SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) > > CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) > > +__SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) > > +__CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) > > #else > > PAGEFLAG_FALSE(SwapCache) > > #endif > > diff --git a/mm/memory.c b/mm/memory.c > > index 2d267ef6621a..02dd62da26e0 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -3128,10 +3128,10 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > > set_page_private(page, entry.val); > > > > /* Tell memcg to use swap ownership records */ > > - SetPageSwapCache(page); > > + __SetPageSwapCache(page); > > err = mem_cgroup_charge(page, vma->vm_mm, > > GFP_KERNEL); > > - ClearPageSwapCache(page); > > + __ClearPageSwapCache(page); > > if (err) { > > ret = VM_FAULT_OOM; > > goto out_page; > > -- > > 2.20.1 > > > > -- > Michal Hocko > SUSE Labs -- Yours, Muchun