walk_page_range() and friends often operate under write-locked mmap_lock.
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas. Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.
The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks. With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them. The change ensures vmas are properly locked during such
walks.
A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration. Without this change a concurrent page
can be faulted into the area and be left out of migration.
Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Suggested-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damos_new_filter() is not initializing the list field of newly allocated
filter object. However, DAMON sysfs interface and DAMON_RECLAIM are not
initializing it after calling damos_new_filter(). As a result, accessing
uninitialized memory is possible. Actually, adding multiple DAMOS filters
via DAMON sysfs interface caused NULL pointer dereferencing. Initialize
the field just after the allocation from damos_new_filter().
Link: https://lkml.kernel.org/r/20230729203733.38949-2-sj@kernel.org
Fixes: 98def236f6 ("mm/damon/core: implement damos filter")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 5ff6e2fff8 ("mm/damon/core: fix divide error in
damon_nr_accesses_to_accesses_bp()") fixed a bug by adding arguments
validation in damon_set_attrs(). Add a unit test for the added validation
to ensure the bug cannot occur again.
Link: https://lkml.kernel.org/r/20230615183323.87561-1-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Convert all instances of direct pte_t* dereferencing to instead use
ptep_get() helper. This means that by default, the accesses change from a
C dereference to a READ_ONCE(). This is technically the correct thing to
do since where pgtables are modified by HW (for access/dirty) they are
volatile and therefore we should always ensure READ_ONCE() semantics.
But more importantly, by always using the helper, it can be overridden by
the architecture to fully encapsulate the contents of the pte. Arch code
is deliberately not converted, as the arch code knows best. It is
intended that arch code (arm64) will override the default with its own
implementation that can (e.g.) hide certain bits from the core code, or
determine young/dirty status by mixing in state from another source.
Conversion was done using Coccinelle:
----
// $ make coccicheck \
// COCCI=ptepget.cocci \
// SPFLAGS="--include-headers" \
// MODE=patch
virtual patch
@ depends on patch @
pte_t *v;
@@
- *v
+ ptep_get(v)
----
Then reviewed and hand-edited to avoid multiple unnecessary calls to
ptep_get(), instead opting to store the result of a single call in a
variable, where it is correct to do so. This aims to negate any cost of
READ_ONCE() and will benefit arch-overrides that may be more complex.
Included is a fix for an issue in an earlier version of this patch that
was pointed out by kernel test robot. The issue arose because config
MMU=n elides definition of the ptep helper functions, including
ptep_get(). HUGETLB_PAGE=n configs still define a simple
huge_ptep_clear_flush() for linking purposes, which dereferences the ptep.
So when both configs are disabled, this caused a build error because
ptep_get() is not defined. Fix by continuing to do a direct dereference
when MMU=n. This is safe because for this config the arch code cannot be
trying to virtualize the ptes because none of the ptep helpers are
defined.
Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Simple walk_page_range() users should set ACTION_AGAIN to retry when
pte_offset_map_lock() fails.
No need to check pmd_trans_unstable(): that was precisely to avoid the
possiblity of calling pte_offset_map() on a racily removed or inserted THP
entry, but such cases are now safely handled inside it. Likewise there is
no need to check pmd_none() or pmd_bad() before calling it.
Link: https://lkml.kernel.org/r/c77d9d10-3aad-e3ce-4896-99e91c7947f3@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: SeongJae Park <sj@kernel.org> for mm/damon part
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Song Liu <song@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zack Rusin <zackr@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With the fix in place to atomically test and clear young on ptes and pmds,
simplify the code to handle the clearing for both the primary mmu and the
mmu notifier with a single API call.
Link: https://lkml.kernel.org/r/20230602092949.545577-4-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is racy to non-atomically read a pte, then clear the young bit, then
write it back as this could discard dirty information. Further, it is bad
practice to directly set a pte entry within a table. Instead clearing
young must go through the arch-provided helper,
ptep_test_and_clear_young() to ensure it is modified atomically and to
give the arch code visibility and allow it to check (and potentially
modify) the operation.
Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces").
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The *folio_sz in damon_pa_young() will be used(as last_folio_sz) by
__damon_pa_check_access(), so it's need to be updated, fix missing branch.
Link: https://lkml.kernel.org/r/20230308083311.120951-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.") the
driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definition to prevent
modification at runtime.
These structures were not constified in commit e56397e8c4
("mm/damon/sysfs: make kobj_type structures constant") as they didn't
exist when that patch was written.
Link: https://lkml.kernel.org/r/20230324-b4-kobj_type-damon2-v1-1-48ddbf1c8fcf@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_pa_mark_accessed_or_deactivate() is accessing a folio via
folio_nr_pages() after folio_put() for the folio has invoked. Fix it.
Link: https://lkml.kernel.org/r/20230304193949.296391-3-sj@kernel.org
Fixes: f70da5ee8f ("mm/damon: convert damon_pa_mark_accessed_or_deactivate() to use folios")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon/paddr: Fix folio-use-after-put bugs".
There are two folio accesses after folio_put() in mm/damon/paddr.c file.
Fix those.
This patch (of 2):
damon_pa_young() is accessing a folio via folio_size() after folio_put()
for the folio has invoked. Fix it.
Link: https://lkml.kernel.org/r/20230304193949.296391-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230304193949.296391-2-sj@kernel.org
Fixes: 397b0c3a58 ("mm/damon/paddr: remove folio_sz field from damon_pa_access_chk_result")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: <stable@vger.kernel.org> [6.2.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
damon_get_folio() would always increase folio _refcount and
folio_isolate_lru() would increase folio _refcount if the folio's lru flag
is set.
If an unevictable folio isolated successfully, there will be two more
_refcount. The one from folio_isolate_lru() will be decreased in
folio_puback_lru(), but the other one from damon_get_folio() will be left
behind. This causes a pin page.
Whatever the case, the _refcount from damon_get_folio() should be
decreased.
Link: https://lkml.kernel.org/r/20230222064223.6735-1-andrew.yang@mediatek.com
Fixes: 57223ac295 ("mm/damon/paddr: support the pageout scheme")
Signed-off-by: andrew.yang <andrew.yang@mediatek.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.16.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Change the return value for page isolation functions", v3.
Now the page isolation functions did not return a boolean to indicate
success or not, instead it will return a negative error when failed
to isolate a page. So below code used in most places seem a boolean
success/failure thing, which can confuse people whether the isolation
is successful.
if (folio_isolate_lru(folio))
continue;
Moreover the page isolation functions only return 0 or -EBUSY, and
most users did not care about the negative error except for few users,
thus we can convert all page isolation functions to return a boolean
value, which can remove the confusion to make code more clear.
No functional changes intended in this patch series.
This patch (of 4):
Now the folio_isolate_lru() did not return a boolean value to indicate
isolation success or not, however below code checking the return value can
make people think that it was a boolean success/failure thing, which makes
people easy to make mistakes (see the fix patch[1]).
if (folio_isolate_lru(folio))
continue;
Thus it's better to check the negative error value expilictly returned by
folio_isolate_lru(), which makes code more clear per Linus's
suggestion[2]. Moreover Matthew suggested we can convert the isolation
functions to return a boolean[3], since most users did not care about the
negative error value, and can also remove the confusing of checking return
value.
So this patch converts the folio_isolate_lru() to return a boolean value,
which means return 'true' to indicate the folio isolation is successful,
and 'false' means a failure to isolation. Meanwhile changing all users'
logic of checking the isolation state.
No functional changes intended.
[1] https://lore.kernel.org/all/20230131063206.28820-1-Kuan-Ying.Lee@mediatek.com/T/#u
[2] https://lore.kernel.org/all/CAHk-=wiBrY+O-4=2mrbVyxR+hOqfdJ=Do6xoucfJ9_5az01L4Q@mail.gmail.com/
[3] https://lore.kernel.org/all/Y+sTFqwMNAjDvxw3@casper.infradead.org/
Link: https://lkml.kernel.org/r/cover.1676424378.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/8a4e3679ed4196168efadf7ea36c038f2f7d5aa9.1676424378.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON debugfs interface has announced to be deprecated after >v5.15 LTS
kernel is released. And, v6.1.y has announced to be an LTS[1].
Though the announcement was there for a while, some people might not
noticed that so far. Also, some users could depend on it and have
problems at movng to the alternative (DAMON sysfs interface).
For such cases, note DAMON debugfs interface as deprecated, and contacts
to ask helps on the Kconfig.
[1] https://git.kernel.org/pub/scm/docs/kernel/website.git/commit/?id=332e9121320bc7461b2d3a79665caf153e51732c
Link: https://lkml.kernel.org/r/20230209192009.7885-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Since commit ee6d3dd4ed ("driver core: make kobj_type constant.") the
driver core allows the usage of const struct kobj_type.
Take advantage of this to constify the structure definitions to prevent
modification at runtime.
Link: https://lkml.kernel.org/r/20230207-kobj_type-damon-v1-1-9d4fea6a465b@weissschuh.net
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Prepare for the removal of the vma_mas_store() function by open coding the
maple tree store in this test code. Set the range of the maple state and
call the store function directly.
Link: https://lkml.kernel.org/r/20230120162650.984577-31-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a simple unit test for damon_update_monitoring_results() function.
Link: https://lkml.kernel.org/r/20230119013831.1911-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
region->nr_accesses is the number of sampling intervals in the last
aggregation interval that access to the region has found, and region->age
is the number of aggregation intervals that its access pattern has
maintained. Hence, the real meaning of the two fields' values is
depending on current sampling and aggregation intervals.
This means the values need to be updated for every sampling and/or
aggregation intervals updates. As DAMON core doesn't, it is a duty of
in-kernel DAMON framework applications like DAMON sysfs interface, or the
userspace users.
Handling it in userspace or in-kernel DAMON application is complicated,
inefficient, and repetitive compared to doing the update in DAMON core.
Do the update in DAMON core.
Link: https://lkml.kernel.org/r/20230119013831.1911-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sometimes there is no scheme in damon's context, for example just use damo
record to monitor workload's data access pattern.
If current damon context doesn't have any scheme in the list, kdamond has
no need to iterate over list of all targets and regions but do nothing.
So, skip apply schemes when ctx->schemes is empty.
Link: https://lkml.kernel.org/r/20230116062347.1148553-1-huaisheng.ye@intel.com
Signed-off-by: Huaisheng Ye <huaisheng.ye@intel.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.
Link: https://lkml.kernel.org/r/202301091946553770006@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
'damon_pa_access_chk_result' struct contains only one field. Use a
variable instead.
Link: https://lkml.kernel.org/r/20230109213335.62525-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON physical address space monitoring operations set gets and saves size
of the folio for a given physical address inside rmap walks, but it can be
directly caluclated outside of the walks. Remove the 'folio_sz' field
from 'damon_pa_access_chk_result struct' and calculate the size directly
from outside of the walks.
Link: https://lkml.kernel.org/r/20230109213335.62525-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON's physical address space monitoring operations set is using folio
now. Rename 'damon_pa_access_chk_result->page_sz' to reflect the fact.
Link: https://lkml.kernel.org/r/20230109213335.62525-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON virtual address spaces monitoring operations set doesn't set folio
size of the access checked address if access is not found. It could
result in unnecessary and inefficient repeated check. Appropriately set
the size regardless of access check result.
Link: https://lkml.kernel.org/r/20230109213335.62525-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON virtual address space monitoring operations set treats folios having
non-HPAGE_PMD_SIZE size as having PAGE_SIZE size. Use the exact size of
the folio.
Link: https://lkml.kernel.org/r/20230109213335.62525-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm/damon/{v,p}addr: misc fixups for folio usage".
DAMON's monitoring operations set for the virtual and the physical address
spaces use folio now, but some code is not reflecting the fact. Further
cleanup the code for folio usage.
This patch (of 6):
DAMON's virtual address space monitoring operations set is using folio
now. Rename 'damon_pa_access_chk_result->page_sz' to reflect the fact.
Link: https://lkml.kernel.org/r/20230109213335.62525-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230109213335.62525-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Convert damon_hugetlb_mkold() and damon_young_hugetlb_entry() to
use a folio.
Link: https://lkml.kernel.org/r/20221230070849.63358-9-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
After all damon_get_page() callers are converted to damon_get_folio(),
remove unneeded wrapper damon_get_page().
Link: https://lkml.kernel.org/r/20221230070849.63358-8-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With damon_get_folio(), let's convert damon_young_pmd_entry()
to use a folio.
Link: https://lkml.kernel.org/r/20221230070849.63358-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With damon_get_folio(), let's convert all the damon_pa_*() to use a folio.
Link: https://lkml.kernel.org/r/20221230070849.63358-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With damon_get_folio(), let's convert damon_ptep_mkold() and
damon_pmdp_mkold() to use a folio.
Link: https://lkml.kernel.org/r/20221230070849.63358-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce damon_get_folio(), and the temporary wrapper function
damon_get_page(), which help us to convert damon related functions to use
folios, and it will be dropped once the conversion is completed.
Link: https://lkml.kernel.org/r/20221230070849.63358-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Deactivate_page() has already been converted to use folios, this change
converts it to take in a folio argument instead of calling page_folio().
It also renames the function folio_deactivate() to be more consistent with
other folio functions.
[akpm@linux-foundation.org: fix left-over comments, per Yu Zhao]
Link: https://lkml.kernel.org/r/20221221180848.20774-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This change replaces 2 calls to compound_head() from put_page() and 1 call
from mark_page_accessed() with one from page_folio(). This is in
preparation for the conversion of deactivate_page() to folio_deactivate().
Link: https://lkml.kernel.org/r/20221221180848.20774-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement 'nr_filters' file under 'filters' directory, which will be used
to populate specific number of 'filter' directory under the directory,
similar to other 'nr_*' files in DAMON sysfs interface.
Link: https://lkml.kernel.org/r/20221205230830.144349-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement DAMOS filter directory which will be located under the filters
directory. The directory provides three files, namely type, matching, and
memcg_path. 'type' and 'matching' will be directly connected to the
fields of 'struct damos_filter' having same name. 'memcg_path' will
receive the path of the memory cgroup of the interest and later converted
to memcg id when it's committed.
Link: https://lkml.kernel.org/r/20221205230830.144349-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMOS filters are currently supported by only DAMON kernel API. To expose
the feature to user space, implement a DAMON sysfs directory named
'filters' under each scheme directory. Please note that this is
implementing only the directory. Following commits will implement more
files and directories, and finally connect the DAMOS filters feature.
Link: https://lkml.kernel.org/r/20221205230830.144349-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In some cases, for example if users have confidence at anonymous pages
management or the swap device is too slow, users would want to avoid
DAMON_RECLAIM swapping the anonymous pages out. For such case, add yet
another DAMON_RECLAIM parameter, namely 'skip_anon'. When it is set as
'Y', DAMON_RECLAIM will avoid reclaiming anonymous pages using a DAMOS
filter.
Link: https://lkml.kernel.org/r/20221205230830.144349-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement support of the DAMOS filters in the physical address space
monitoring operations set, for all DAMOS actions that it supports
including 'pageout', 'lru_prio', and 'lru_deprio'.
Link: https://lkml.kernel.org/r/20221205230830.144349-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "implement DAMOS filtering for anon pages and/or specific
memory cgroups"
DAMOS let users do system operations in a data access pattern oriented
way. The data access pattern, which is extracted by DAMON, is somewhat
accurate more than what user space could know in many cases. However, in
some situation, users could know something more than the kernel about the
pattern or some special requirements for some types of memory or
processes. For example, some users would have slow swap devices and knows
latency-ciritical processes and therefore want to use DAMON-based
proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of
non-latency-critical processes.
For such restriction, users could exclude the memory regions from the
initial monitoring regions and use non-dynamic monitoring regions update
monitoring operations set including fvaddr and paddr. They could also
adjust the DAMOS target access pattern. For dynamically changing memory
layout and access pattern, those would be not enough.
To help the case, add an interface, namely DAMOS filters, which can be
used to avoid the DAMOS actions be applied to specific types of memory, to
DAMON kernel API (damon.h). At the moment, it supports filtering
anonymous pages and/or specific memory cgroups in or out for each DAMOS
scheme.
This patchset adds the support for all DAMOS actions that 'paddr'
monitoring operations set supports ('pageout', 'lru_prio', and
'lru_deprio'), and the functionality is exposed via DAMON kernel API
(damon.h) the DAMON sysfs interface (/sys/kernel/mm/damon/admins/), and
DAMON_RECLAIM module parameters.
Patches Sequence
----------------
First patch implements DAMOS filter interface to DAMON kernel API. Second
patch makes the physical address space monitoring operations set to
support the filters from all supporting DAMOS actions. Third patch adds
anonymous pages filter support to DAMON_RECLAIM, and the fourth patch
documents the DAMON_RECLAIM's new feature. Fifth to seventh patches
implement DAMON sysfs files for support of the filters, and eighth patch
connects the file to use DAMOS filters feature. Ninth patch adds simple
self test cases for DAMOS filters of the sysfs interface. Finally,
following two patches (tenth and eleventh) document the new features and
interfaces.
This patch (of 11):
DAMOS lets users do system operation in a data access pattern oriented
way. The data access pattern, which is extracted by DAMON, is somewhat
accurate more than what user space could know in many cases. However, in
some situation, users could know something more than the kernel about the
pattern or some special requirements for some types of memory or
processes. For example, some users would have slow swap devices and knows
latency-ciritical processes and therefore want to use DAMON-based
proactive reclamation (DAMON_RECLAIM) for only non-anonymous pages of
non-latency-critical processes.
For such restriction, users could exclude the memory regions from the
initial monitoring regions and use non-dynamic monitoring regions update
monitoring operations set including fvaddr and paddr. They could also
adjust the DAMOS target access pattern. For dynamically changing memory
layout and access pattern, those would be not enough.
To help the case, add an interface, namely DAMOS filters, which can be
used to avoid the DAMOS actions be applied to specific types of memory, to
DAMON kernel API (damon.h). At the moment, it supports filtering
anonymous pages and/or specific memory cgroups in or out for each DAMOS
scheme.
Note that this commit adds only the interface to the DAMON kernel API.
The impelmentation should be made in the monitoring operations sets, and
following commits will add that.
Link: https://lkml.kernel.org/r/20221205230830.144349-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20221205230830.144349-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
strtobool() is the same as kstrtobool(). However, the latter is more used
within the kernel.
In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.
While at it, include the corresponding header file (<linux/kstrtox.h>)
Link: https://lkml.kernel.org/r/ed2b46489a513988688decb53850339cc228940c.1667336095.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When there are huge number of DAMON regions that specific scheme actions
are tried to be applied, directories and files under 'tried_regions'
scheme directory could waste some memory. Add another special input
keyword ('clear_schemes_tried_regions') for 'state' file of each kdamond
sysfs directory that can be used for cleanup of the 'tried_regions'
sub-directories.
[sj@kernel.org: skip regions clearing if the scheme directory was removed]
Link: https://lkml.kernel.org/r/20221114182954.4745-3-sj@kernel.org
Link: https://lkml.kernel.org/r/20221101220328.95765-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Implement the code for filling the data of 'tried_regions' DAMON sysfs
directory. With this commit, DAMON sysfs interface users can write a
special keyword, 'update_schemes_tried_regions' to the corresponding
'state' file of the kdamond. Then, DAMON sysfs interface will collect the
tried regions information using the 'before_damos_apply()' callback for
one aggregation interval and populate scheme region directories with the
values.
[sj@kernel.org: skip tried regions update if the scheme directory was removed]
Link: https://lkml.kernel.org/r/20221114182954.4745-2-sj@kernel.org
Link: https://lkml.kernel.org/r/20221101220328.95765-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
