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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 5DC88180003 X-Stat-Signature: amt5qtq4d1ykpb7hjtawzcj4c1i6qfz9 X-HE-Tag: 1712917200-880466 X-HE-Meta: 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 umxOzCes 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 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: List-Subscribe: List-Unsubscribe: On 12/04/2024 08:37, Barry Song wrote: > From: Barry Song > > This patch includes documentation for mTHP counters and an ABI file > for sys-kernel-mm-transparent-hugepage, which appears to have been > missing for some time. > > Signed-off-by: Barry Song > Cc: Chris Li > Cc: David Hildenbrand > Cc: Domenico Cerasuolo > Cc: Kairui Song > Cc: Matthew Wilcox (Oracle) > Cc: Peter Xu > Cc: Ryan Roberts > Cc: Suren Baghdasaryan > Cc: Yosry Ahmed > Cc: Yu Zhao > Cc: Jonathan Corbet A few nits, but regardless: Reviewed-by: Ryan Roberts > --- > .../sys-kernel-mm-transparent-hugepage | 17 +++++++++++ > Documentation/admin-guide/mm/transhuge.rst | 28 +++++++++++++++++++ > 2 files changed, 45 insertions(+) > create mode 100644 Documentation/ABI/testing/sys-kernel-mm-transparent-hugepage > > diff --git a/Documentation/ABI/testing/sys-kernel-mm-transparent-hugepage b/Documentation/ABI/testing/sys-kernel-mm-transparent-hugepage > new file mode 100644 > index 000000000000..80dde0fd576c > --- /dev/null > +++ b/Documentation/ABI/testing/sys-kernel-mm-transparent-hugepage > @@ -0,0 +1,17 @@ > +What: /sys/kernel/mm/hugepages/ Err, transparent_hugepage, right? copy/paste error? > +Date: April 2024 > +Contact: Barry Song Looks like a bunch of mm sysfs interfaces use: Contact: Linux memory management mailing list I'll leave that up to you! > +Description: > + /sys/kernel/mm/transparent_hugepage/ contains a number of files and > + subdirectories, > + - defrag > + - enabled > + - hpage_pmd_size > + - khugepaged > + - shmem_enabled > + - use_zero_page > + - subdirectories of the form hugepages-kB, where > + is the page size of the hugepages supported by the kernel/CPU > + combination. > + > + See Documentation/admin-guide/mm/transhuge.rst for details.> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst > index 04eb45a2f940..f436ff982f22 100644 > --- a/Documentation/admin-guide/mm/transhuge.rst > +++ b/Documentation/admin-guide/mm/transhuge.rst > @@ -447,6 +447,34 @@ thp_swpout_fallback > Usually because failed to allocate some continuous swap space > for the huge page. > > +In /sys/kernel/mm/transparent_hugepage/hugepages-kB/stats, There are > +also individual counters for each huge page size, which can be utilized to > +monitor the system's effectiveness in providing huge pages for usage. Each > +counter has its own corresponding file. > + > +anon_fault_alloc > + is incremented every time a huge page is successfully > + allocated and charged to handle a page fault. > + > +anon_fault_fallback > + is incremented if a page fault fails to allocate or charge > + a huge page and instead falls back to using huge pages with > + lower orders or small pages. > + > +anon_fault_fallback_charge > + is incremented if a page fault fails to charge a huge page and > + instead falls back to using huge pages with lower orders or > + small pages even though the allocation was successful. > + > +anon_swpout > + is incremented every time a huge page is swapout in one nit: swapout -> "swapped out"? Although I see this is just a copy/paste of the description of the existing counter... > + piece without splitting. > + > +anon_swpout_fallback > + is incremented if a huge page has to be split before swapout. > + Usually because failed to allocate some continuous swap space > + for the huge page. > + > As the system ages, allocating huge pages may be expensive as the > system uses memory compaction to copy data around memory to free a > huge page for use. There are some counters in ``/proc/vmstat`` to help