| Message ID | 20201019101520.12283-1-songmuchun@bytedance.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm/memory.c: Introduce non-atomic __{Set,Clear}PageSwapCache | expand |
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. No objection to the change. > Signed-off-by: Muchun Song <songmuchun@bytedance.com> With an improved changelog Acked-by: Michal Hocko <mhocko@suse.com> > --- > 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 >
On Mon, Oct 19, 2020 at 8:31 PM Michal Hocko <mhocko@suse.com> 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 <songmuchun@bytedance.com> > > With an improved changelog > Acked-by: Michal Hocko <mhocko@suse.com> > > > --- > > 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
On 10/19/20 10:58 PM, Muchun Song wrote: > On Mon, Oct 19, 2020 at 8:31 PM Michal Hocko <mhocko@suse.com> 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 <songmuchun@bytedance.com> >> >> With an improved changelog >> Acked-by: Michal Hocko <mhocko@suse.com> >> >>> --- >>> 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); Good evening, Muchun. I found there are still some places could be replaced with __SetPageSwapCache（）. Such as shmem_replace_page（）, why PG_locked has been set before SetPageSwapCache（） is involved. Would you please to check the rest places? :) Thanks Acked-by: Yanfei Xu <yanfei.xu@windriver.com> >>> 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 > > >
On Tue, Oct 20, 2020 at 7:51 PM Xu, Yanfei <yanfei.xu@windriver.com> wrote: > > > > On 10/19/20 10:58 PM, Muchun Song wrote: > > On Mon, Oct 19, 2020 at 8:31 PM Michal Hocko <mhocko@suse.com> 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 <songmuchun@bytedance.com> > >> > >> With an improved changelog > >> Acked-by: Michal Hocko <mhocko@suse.com> > >> > >>> --- > >>> 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); > > Good evening, Muchun. I found there are still some places could be > replaced with __SetPageSwapCache（）. Such as shmem_replace_page（）, why Yeah, thanks for your suggestion. > PG_locked has been set before SetPageSwapCache（） is involved. In this case, It doesn't matter whether PG_locked is set before SetPageSwapCache. > > Would you please to check the rest places? :) Ok, I'll take a look. Thanks. > > Thanks > > Acked-by: Yanfei Xu <yanfei.xu@windriver.com> > > >>> 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
On 10/20/20 9:08 PM, Muchun Song wrote: > On Tue, Oct 20, 2020 at 7:51 PM Xu, Yanfei <yanfei.xu@windriver.com> wrote: >> >> >> >> On 10/19/20 10:58 PM, Muchun Song wrote: >>> On Mon, Oct 19, 2020 at 8:31 PM Michal Hocko <mhocko@suse.com> 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 <songmuchun@bytedance.com> >>>> >>>> With an improved changelog >>>> Acked-by: Michal Hocko <mhocko@suse.com> >>>> >>>>> --- >>>>> 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); >> >> Good evening, Muchun. I found there are still some places could be >> replaced with __SetPageSwapCache（）. Such as shmem_replace_page（）, why > > Yeah, thanks for your suggestion. > >> PG_locked has been set before SetPageSwapCache（） is involved. > > In this case, It doesn't matter whether PG_locked is set before > SetPageSwapCache. > Sorry for this mistake. PG_locked is used for disk I/O. >> >> Would you please to check the rest places? :) > > Ok, I'll take a look. Thanks. > >> >> Thanks >> >> Acked-by: Yanfei Xu <yanfei.xu@windriver.com> >> >>>>> 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 >
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;
For the exclusive reference page, the non-atomic operations is enough, so replace them to non-atomic operations. Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- include/linux/page-flags.h | 2 ++ mm/memory.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-)