| Message ID | 20240424135148.30422-1-ioworker0@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | mm: introduce per-order mTHP split counters | expand |
On 24.04.24 15:51, Lance Yang wrote: > Hi all, > > At present, the split counters in THP statistics no longer include > PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split > counters to monitor the frequency of mTHP splits. This will assist > developers in better analyzing and optimizing system performance. > > /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats > split_page > split_page_failed > deferred_split_page > > Thanks, > Lance > --- > > Lance Yang (2): > mm: add per-order mTHP split counters > mm: add docs for per-order mTHP split counters > > Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- We really have to start documenting these, and what the sementics are. E.g., is split_page_failed contained in split_page? Is deferred_split_page contained in split_page? But also: just don't call it "split_page". Drop the "_page". split split_failed split_deferred ?
On 24/04/2024 16:00, David Hildenbrand wrote: > On 24.04.24 15:51, Lance Yang wrote: >> Hi all, >> >> At present, the split counters in THP statistics no longer include >> PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split >> counters to monitor the frequency of mTHP splits. This will assist >> developers in better analyzing and optimizing system performance. >> >> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats >> split_page >> split_page_failed >> deferred_split_page >> >> Thanks, >> Lance >> --- >> >> Lance Yang (2): >> mm: add per-order mTHP split counters >> mm: add docs for per-order mTHP split counters >> >> Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- > > We really have to start documenting these, and what the sementics are. I think the diffstat is backwards; the series definitely adds more lines than it removes. And patch 2 is adding 16 lines of docs, not removing them. How are you generating this? `git format-patch` should do it correctly for you. > > E.g., is split_page_failed contained in split_page? Is deferred_split_page > contained in split_page? > > But also: just don't call it "split_page". Drop the "_page". > > split > split_failed > split_deferred I guess we are back in "should we be consistent with the existing vmstats" territory, which uses split_page/split_page_failed/deferred_split_page But here, I agree that dropping _page is nicer. > > ? >
On 24.04.24 17:20, Ryan Roberts wrote: > On 24/04/2024 16:00, David Hildenbrand wrote: >> On 24.04.24 15:51, Lance Yang wrote: >>> Hi all, >>> >>> At present, the split counters in THP statistics no longer include >>> PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split >>> counters to monitor the frequency of mTHP splits. This will assist >>> developers in better analyzing and optimizing system performance. >>> >>> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats >>> split_page >>> split_page_failed >>> deferred_split_page >>> >>> Thanks, >>> Lance >>> --- >>> >>> Lance Yang (2): >>> mm: add per-order mTHP split counters >>> mm: add docs for per-order mTHP split counters >>> >>> Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- >> >> We really have to start documenting these, and what the sementics are. > > I think the diffstat is backwards; the series definitely adds more lines than it > removes. And patch 2 is adding 16 lines of docs, not removing them. How are you > generating this? `git format-patch` should do it correctly for you. > >> >> E.g., is split_page_failed contained in split_page? Is deferred_split_page >> contained in split_page? >> >> But also: just don't call it "split_page". Drop the "_page". >> >> split >> split_failed >> split_deferred > > I guess we are back in "should we be consistent with the existing vmstats" > territory, which uses split_page/split_page_failed/deferred_split_page > Yeah, "thp_split_page" really is odd "transparent huge page split page". > But here, I agree that dropping _page is nicer. Right; we also shouldn't call it "thp_split_page" here :)
On Wed, Apr 24, 2024 at 11:29 PM David Hildenbrand <david@redhat.com> wrote: > > On 24.04.24 17:20, Ryan Roberts wrote: > > On 24/04/2024 16:00, David Hildenbrand wrote: > >> On 24.04.24 15:51, Lance Yang wrote: > >>> Hi all, > >>> > >>> At present, the split counters in THP statistics no longer include > >>> PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split > >>> counters to monitor the frequency of mTHP splits. This will assist > >>> developers in better analyzing and optimizing system performance. > >>> > >>> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats > >>> split_page > >>> split_page_failed > >>> deferred_split_page > >>> > >>> Thanks, > >>> Lance > >>> --- > >>> > >>> Lance Yang (2): > >>> mm: add per-order mTHP split counters > >>> mm: add docs for per-order mTHP split counters > >>> > >>> Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- > >> > >> We really have to start documenting these, and what the sementics are. > > > > I think the diffstat is backwards; the series definitely adds more lines than it > > removes. And patch 2 is adding 16 lines of docs, not removing them. How are you > > generating this? `git format-patch` should do it correctly for you. > > > >> > >> E.g., is split_page_failed contained in split_page? Is deferred_split_page > >> contained in split_page? > >> > >> But also: just don't call it "split_page". Drop the "_page". > >> > >> split > >> split_failed > >> split_deferred > > > > I guess we are back in "should we be consistent with the existing vmstats" > > territory, which uses split_page/split_page_failed/deferred_split_page > > > > Yeah, "thp_split_page" really is odd "transparent huge page split page". > > > But here, I agree that dropping _page is nicer. > Right; we also shouldn't call it "thp_split_page" here :) Yep, I understood. Let's drop the "_page". split split_failed split_deferred Thanks, Lance > > -- > Cheers, > > David / dhildenb >
On Wed, Apr 24, 2024 at 11:20 PM Ryan Roberts <ryan.roberts@arm.com> wrote: > > On 24/04/2024 16:00, David Hildenbrand wrote: > > On 24.04.24 15:51, Lance Yang wrote: > >> Hi all, > >> > >> At present, the split counters in THP statistics no longer include > >> PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split > >> counters to monitor the frequency of mTHP splits. This will assist > >> developers in better analyzing and optimizing system performance. > >> > >> /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats > >> split_page > >> split_page_failed > >> deferred_split_page > >> > >> Thanks, > >> Lance > >> --- > >> > >> Lance Yang (2): > >> mm: add per-order mTHP split counters > >> mm: add docs for per-order mTHP split counters > >> > >> Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- > > > > We really have to start documenting these, and what the sementics are. > > I think the diffstat is backwards; the series definitely adds more lines than it Good spot! I'll sort it out. Thanks, Lance > removes. And patch 2 is adding 16 lines of docs, not removing them. How are you > generating this? `git format-patch` should do it correctly for you. > > > > > E.g., is split_page_failed contained in split_page? Is deferred_split_page > > contained in split_page? > > > > But also: just don't call it "split_page". Drop the "_page". > > > > split > > split_failed > > split_deferred > > I guess we are back in "should we be consistent with the existing vmstats" > territory, which uses split_page/split_page_failed/deferred_split_page > > But here, I agree that dropping _page is nicer. > > > > > ? > > >
Hi all, At present, the split counters in THP statistics no longer include PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split counters to monitor the frequency of mTHP splits. This will assist developers in better analyzing and optimizing system performance. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats split_page split_page_failed deferred_split_page Thanks, Lance --- Lance Yang (2): mm: add per-order mTHP split counters mm: add docs for per-order mTHP split counters Documentation/admin-guide/mm/transhuge.rst | 16 ---------------- include/linux/huge_mm.h | 3 --- mm/huge_memory.c | 14 ++------------ 3 files changed, 2 insertions(+), 31 deletions(-)