maintainer-profile.rst for DAMON separates the links and target
definitions. It is not really necessary, and only makes the readability
worse. At least the definitions need the section title (say,
"References"). Just add the links in place on the doc.
Link: https://lkml.kernel.org/r/20240826015741.80707-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Docs/damon: update GitHub repo URLs and maintainer-profile".
Replace GitHub URLS on DAMON documents for none-kernel parts DAMON repos
with new ones[1] via the first patch. With following two patches,
wordsmith maitnainer-profile for better readability, and document the
Google clendsar for bi-weekly meetups, respectively.
[1] https://lore.kernel.org/20240813232158.83903-1-sj@kernel.org
This patch (of 3):
GitHub repos for non-kernel parts of DAMON project including 'damo',
'damon-tests' and 'damoos' will be moved[1] from 'awslabs' org to
'damonitor', by 2024-09-05. Update related URLs in kernel tree.
[1] https://lore.kernel.org/20240813232158.83903-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240826015741.80707-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240826015741.80707-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Alex Shi <alexs@kernel.org>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This reverts commit 0742cadf5e4c ("mm/damon/lru_sort: adjust local
variable to dynamic allocation").
The commit was introduced to avoid unnecessary usage of stack memory for
per-scheme region priorities histogram buffer. The fix is nice, but the
point of the fix looks not very clear if the commit message is not read
together. That's mainly because the buffer is a private field, which
means it is hidden from the DAMON API users. That's not the fault of the
fix but the underlying data structure.
Now the per-scheme histogram buffer is gone, so the problem that the
commit was fixing is also removed. The use of kmemdup() has no more point
but just making the code bit difficult to understand. Revert the fix.
Link: https://lkml.kernel.org/r/20240826042323.87025-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Nobody is reading from or writing to the per-scheme region priorities
histogram buffer. It is only wasting memory. Remove it.
Link: https://lkml.kernel.org/r/20240826042323.87025-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace the usage of per-quota region priorities histogram buffer with the
per-context one. After this change, the per-quota histogram is not used
by anyone, and hence it is ready to be removed.
Link: https://lkml.kernel.org/r/20240826042323.87025-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "replace per-quota region priorities histogram buffer with
per-context one".
Each DAMOS quota (struct damos_quota) maintains a histogram for total
regions size per its prioritization score. DAMOS calcultes minimum
prioritization score of regions that are ok to apply the DAMOS action to
while respecting the quota. The histogram is constructed only for the
calculation of the minimum score in damos_adjust_quota() for each quota
which called by kdamond_fn().
Hence, there is no real reason to have per-quota histogram. Only
per-kdamond histogram is needed, since parallel kdamonds could have races
otherwise. The current implementation is only wasting the memory, and can
easily cause unintended stack usage[1].
So, introducing a per-kdamond histogram and replacing the per-quota one
with it would be the right solution for the issue. However, supporting
multiple DAMON contexts per kdamond is still an ongoing work[2] without a
clear estimated time of arrival. Meanwhile, per-context histogram could
be an effective and straightforward solution having no blocker. Let's fix
the problem first in the way.
This patch (of 4):
Introduce per-context buffer for region priority scores-total size
histogram. Same to the per-quota one (->histogram of struct damos_quota),
the new buffer is hidden from DAMON API users by being defined as a
private field of DAMON context structure. It is dynamically allocated and
de-allocated at the beginning and ending of the execution of the kdamond
by kdamond_fn() itself.
[1] commit 0742cadf5e4c ("mm/damon/lru_sort: adjust local variable to dynamic allocation")
[2] https://lore.kernel.org/20240531122320.909060-1-yorha.op@gmail.com
Link: https://lkml.kernel.org/r/20240826042323.87025-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240826042323.87025-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There are no more callers of putback_lru_page(), remove it.
Link: https://lkml.kernel.org/r/20240826065814.1336616-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There are no more callers of isolate_lru_page(), remove it.
[wangkefeng.wang@huawei.com: convert page to folio in comment and document, per Matthew]
Link: https://lkml.kernel.org/r/20240826144114.1928071-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Saves a couple of calls to compound_head() and remove last two callers of
putback_lru_page().
Link: https://lkml.kernel.org/r/20240826065814.1336616-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The page for migrate_device_unmap() already has a reference, so it is safe
to convert the page to folio to save a few calls to compound_head(), which
removes the last isolate_lru_page() call.
Link: https://lkml.kernel.org/r/20240826065814.1336616-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Save two calls to compound_head() and use folio throughout.
Link: https://lkml.kernel.org/r/20240826065814.1336616-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: finish isolate/putback_lru_page()".
Convert to use more folios in migrate_device.c, then we could remove
isolate_lru_page() and putback_lru_page().
This patch (of 6):
Save a few calls to compound_head() and use folio throughout.
Link: https://lkml.kernel.org/r/20240826065814.1336616-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Retrieve a folio from the page cache rather than a page. Saves a couple
of conversions between page & folio.
Link: https://lkml.kernel.org/r/20240826202138.3804238-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When a THP is added to the deferred_list due to partially mapped, its
partial pages are unused, leading to wasted memory and potentially
increasing memory reclamation pressure.
Detailing the specifics of how unmapping occurs is quite difficult and not
that useful, so we adopt a simple approach: each time a THP enters the
deferred_list, we increment the count by 1; whenever it leaves for any
reason, we decrement the count by 1.
Link: https://lkml.kernel.org/r/20240824010441.21308-3-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuai Yuan <yuanshuai@oppo.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: count the number of anonymous THPs per size", v4.
Knowing the number of transparent anon THPs in the system is crucial
for performance analysis. It helps in understanding the ratio and
distribution of THPs versus small folios throughout the system.
Additionally, partial unmapping by userspace can lead to significant waste
of THPs over time and increase memory reclamation pressure. We need this
information for comprehensive system tuning.
This patch (of 2):
Let's track for each anonymous THP size, how many of them are currently
allocated. We'll track the complete lifespan of an anon THP, starting
when it becomes an anon THP ("large anon folio") (->mapping gets set),
until it gets freed (->mapping gets cleared).
Introduce a new "nr_anon" counter per THP size and adjust the
corresponding counter in the following cases:
* We allocate a new THP and call folio_add_new_anon_rmap() to map
it the first time and turn it into an anon THP.
* We split an anon THP into multiple smaller ones.
* We migrate an anon THP, when we prepare the destination.
* We free an anon THP back to the buddy.
Note that AnonPages in /proc/meminfo currently tracks the total number of
*mapped* anonymous *pages*, and therefore has slightly different
semantics. In the future, we might also want to track "nr_anon_mapped"
for each THP size, which might be helpful when comparing it to the number
of allocated anon THPs (long-term pinning, stuck in swapcache, memory
leaks, ...).
Further note that for now, we only track anon THPs after they got their
->mapping set, for example via folio_add_new_anon_rmap(). If we would
allocate some in the swapcache, they will only show up in the statistics
for now after they have been mapped to user space the first time, where we
call folio_add_new_anon_rmap().
[akpm@linux-foundation.org: documentation fixups, per David]
Link: https://lkml.kernel.org/r/3e8add35-e26b-443b-8a04-1078f4bc78f6@redhat.com
Link: https://lkml.kernel.org/r/20240824010441.21308-1-21cnbao@gmail.com
Link: https://lkml.kernel.org/r/20240824010441.21308-2-21cnbao@gmail.com
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Chuanhua Han <hanchuanhua@oppo.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuai Yuan <yuanshuai@oppo.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Previously we had a situation where shmem mTHP controls and stats were not
exposed for some supported sizes and were exposed for some unsupported
sizes. So let's clean that up.
Anon mTHP can support all large orders [2, PMD_ORDER]. But shmem can
support all large orders [1, MAX_PAGECACHE_ORDER]. However, per-size
shmem controls and stats were previously being exposed for all the anon
mTHP orders, meaning order-1 was not present, and for arm64 64K base
pages, orders 12 and 13 were exposed but were not supported internally.
Tidy this all up by defining ctrl and stats attribute groups for anon and
file separately. Anon ctrl and stats groups are populated for all orders
in THP_ORDERS_ALL_ANON and file ctrl and stats groups are populated for
all orders in THP_ORDERS_ALL_FILE_DEFAULT.
Additionally, create "any" ctrl and stats attribute groups which are
populated for all orders in (THP_ORDERS_ALL_ANON |
THP_ORDERS_ALL_FILE_DEFAULT). swpout stats use this since they apply to
anon and shmem.
The side-effect of all this is that different hugepage-*kB directories
contain different sets of controls and stats, depending on which memory
types support that size. This approach is preferred over the alternative,
which is to populate dummy controls and stats for memory types that do not
support a given size.
[ryan.roberts@arm.com: file pages and shmem can also be split]
Link: https://lkml.kernel.org/r/f7ced14c-8bc5-405f-bee7-94f63980f525@arm.comLink: https://lkml.kernel.org/r/20240808111849.651867-3-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Tested-by: Barry Song <baohua@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Shmem mTHP controls and stats improvements", v3.
This is a small series to tidy up the way the shmem controls and stats are
exposed. These patches were previously part of the series at [2], but I
decided to split them out since they can go in independently.
This patch (of 2):
Let's move count_mthp_stat() so that it's always defined, even when THP is
disabled. Previously uses of the function in files such as shmem.c, which
are compiled even when THP is disabled, required ugly THP ifdeferry. With
this cleanup, we can remove those ifdefs and the function resolves to a
nop when THP is disabled.
I shortly plan to call count_mthp_stat() from more THP-invariant source
files.
Link: https://lkml.kernel.org/r/20240808111849.651867-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20240808111849.651867-2-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Barry Song <baohua@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Lance Yang <ioworker0@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the isolate_folio_to_list() to unify hugetlb/LRU/non-LRU folio
isolation, which cleanup code a bit and save a few calls to
compound_head().
[wangkefeng.wang@huawei.com: various fixes]
Link: https://lkml.kernel.org/r/20240829150500.2599549-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add isolate_folio_to_list() helper to try to isolate HugeTLB, no-LRU
movable and LRU folios to a list, which will be reused by
do_migrate_range() from memory hotplug soon, also drop the
mf_isolate_folio() since we could directly use new helper in the
soft_offline_in_use_page().
Link: https://lkml.kernel.org/r/20240827114728.3212578-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit b15c87263a ("hwpoison, memory_hotplug: allow hwpoisoned pages to
be offlined") don't handle the hugetlb pages, the endless loop still occur
if offline a hwpoison hugetlb page, luckly, after the commit e591ef7d96
("mm, hwpoison,hugetlb,memory_hotplug: hotremove memory section with
hwpoisoned hugepage"), the HPageMigratable of hugetlb page will be
cleared, and the hwpoison hugetlb page will be skipped in
scan_movable_pages(), so the endless loop issue is fixed.
However if the HPageMigratable() check passed(without reference and lock),
the hugetlb page may be hwpoisoned, it won't cause issue since the
hwpoisoned page will be handled correctly in the next movable pages scan
loop, and it will be isolated in do_migrate_range() but fails to migrate.
In order to avoid the unnecessary isolation and unify all hwpoisoned page
handling, let's unconditionally check hwpoison firstly, and if it is a
hwpoisoned hugetlb page, try to unmap it as the catch all safety net like
normal page does.
Link: https://lkml.kernel.org/r/20240827114728.3212578-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add unmap_poisoned_folio() helper which will be reused by
do_migrate_range() from memory hotplug soon.
[akpm@linux-foundation.org: whitespace tweak, per Miaohe Lin]
Link: https://lkml.kernel.org/r/1f80c7e3-c30d-1ac1-6a36-d1a5f5907f7c@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: memory_hotplug: improve do_migrate_range()", v3.
Unify hwpoisoned page handling and isolation of HugeTLB/LRU/non-LRU
movable page, also convert to use folios in do_migrate_range().
This patch (of 5):
Directly use a folio for HugeTLB and THP when calculate the next pfn, then
remove unused head variable.
Link: https://lkml.kernel.org/r/20240827114728.3212578-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
'--kunitconfig' option of 'kunit.py run' supports '.kunitconfig' file name
convention. Add the file for DAMON kunit tests for more convenient kunit
run.
Link: https://lkml.kernel.org/r/20240827030336.7930-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The test depends on registration of DAMON_OPS_PADDR. It would be
registered only when CONFIG_DAMON_PADDR is set. DAMON core kunit tests do
fake ops registration for such case. However, the functions for such fake
ops registration is not available to DAMON debugfs interface. Just skip
the test in the case.
Link: https://lkml.kernel.org/r/20240827030336.7930-8-sj@kernel.org
Fixes: 999b946797 ("mm/damon/dbgfs-test: fix is_target_id() change")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The test depends on registration of DAMON_OPS_PADDR. It would be
registered only when CONFIG_DAMON_PADDR is set. DAMON core kunit tests do
fake ops registration for such case. However, the functions for such fake
ops registration is not available to DAMON debugfs interface. Just skip
the test in the case.
Link: https://lkml.kernel.org/r/20240827030336.7930-7-sj@kernel.org
Fixes: 999b946797 ("mm/damon/dbgfs-test: fix is_target_id() change")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON core kunit test can be executed without CONFIG_DAMON_VADDR. In the
case, vaddr DAMON ops is not registered. Meanwhile, ops registration
kunit test assumes the vaddr ops is registered. Check and handle the case
by registrering fake vaddr ops inside the test code.
Link: https://lkml.kernel.org/r/20240827030336.7930-6-sj@kernel.org
Fixes: 4f540f5ab4 ("mm/damon/core-test: add a kunit test case for ops registration")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON ops registration kunit test tests both vaddr and paddr use cases in
parts of the whole test cases. Basically testing only one ops use case is
enough. Do the test with only vaddr use case.
Link: https://lkml.kernel.org/r/20240827030336.7930-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Some test scripts are missing executable permissions. It causes warnings
that make the test output unnecessarily verbose. Add executable
permissions.
Link: https://lkml.kernel.org/r/20240827030336.7930-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Python-based tests creates __pycache__/ directory. Remove it with 'make
clean' by defining it as EXTRA_CLEAN.
Link: https://lkml.kernel.org/r/20240827030336.7930-3-sj@kernel.org
Fixes: b5906f5f73 ("selftests/damon: add a test for update_schemes_tried_regions sysfs command")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "misc fixups for DAMON {self,kunit} tests".
This patchset is for minor fixups of DAMON selftests and kunit tests.
First three patches make DAMON selftests more cleanly maintained (patches
1 and 2) without unnecessary warnings (patch 3). Following six patches
remove unnecessary test case (patch 4), handle configs combinations that
can make tests fail (patches 5-7), reorganize the test files following the
new guideline (patch 8), and add reference kunitconfig for DAMON kunit
tests (patch 9).
This patch (of 9):
DAMON selftests build access_memory_even, but its not on the .gitignore
list. Add it to make 'git status' output cleaner.
Link: https://lkml.kernel.org/r/20240827030336.7930-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20240827030336.7930-2-sj@kernel.org
Fixes: c94df805c7 ("selftests/damon: implement a program for even-numbered memory regions access")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Problem statement:
Since commit fc137c0dda ("sched/numa: enhance vma scanning logic"), the
Numa vma scan overhead has been reduced a lot. Meanwhile, the reducing of
the vma scan might create less Numa page fault information. The
insufficient information makes it harder for the Numa balancer to make
decision. Later, commit b7a5b537c5 ("sched/numa: Complete scanning of
partial VMAs regardless of PID activity") and commit 84db47ca71
("sched/numa: Fix mm numa_scan_seq based unconditional scan") are found to
bring back part of the performance.
Recently when running SPECcpu omnetpp_r on a 320 CPUs/2 Sockets system, a
long duration of remote Numa node read was observed by PMU events: A few
cores having ~500MB/s remote memory access for ~20 seconds. It causes
high core-to-core variance and performance penalty. After the
investigation, it is found that many vmas are skipped due to the active
PID check. According to the trace events, in most cases,
vma_is_accessed() returns false because the history access info stored in
pids_active array has been cleared.
Proposal:
The main idea is to adjust vma_is_accessed() to let it return true easier.
Thus compare the diff between mm->numa_scan_seq and
vma->numab_state->prev_scan_seq. If the diff has exceeded the threshold,
scan the vma.
This patch especially helps the cases where there are small number of
threads, like the process-based SPECcpu. Without this patch, if the
SPECcpu process access the vma at the beginning, then sleeps for a long
time, the pid_active array will be cleared. A a result, if this process
is woken up again, it never has a chance to set prot_none anymore.
Because only the first 2 times of access is granted for vma scan:
(current->mm->numa_scan_seq) - vma->numab_state->start_scan_seq) < 2 to be
worse, no other threads within the task can help set the prot_none. This
causes information lost.
Raghavendra helped test current patch and got the positive result
on the AMD platform:
autonumabench NUMA01
base patched
Amean syst-NUMA01 194.05 ( 0.00%) 165.11 * 14.92%*
Amean elsp-NUMA01 324.86 ( 0.00%) 315.58 * 2.86%*
Duration User 380345.36 368252.04
Duration System 1358.89 1156.23
Duration Elapsed 2277.45 2213.25
autonumabench NUMA02
Amean syst-NUMA02 1.12 ( 0.00%) 1.09 * 2.93%*
Amean elsp-NUMA02 3.50 ( 0.00%) 3.56 * -1.84%*
Duration User 1513.23 1575.48
Duration System 8.33 8.13
Duration Elapsed 28.59 29.71
kernbench
Amean user-256 22935.42 ( 0.00%) 22535.19 * 1.75%*
Amean syst-256 7284.16 ( 0.00%) 7608.72 * -4.46%*
Amean elsp-256 159.01 ( 0.00%) 158.17 * 0.53%*
Duration User 68816.41 67615.74
Duration System 21873.94 22848.08
Duration Elapsed 506.66 504.55
Intel 256 CPUs/2 Sockets:
autonuma benchmark also shows improvements:
v6.10-rc5 v6.10-rc5
+patch
Amean syst-NUMA01 245.85 ( 0.00%) 230.84 * 6.11%*
Amean syst-NUMA01_THREADLOCAL 205.27 ( 0.00%) 191.86 * 6.53%*
Amean syst-NUMA02 18.57 ( 0.00%) 18.09 * 2.58%*
Amean syst-NUMA02_SMT 2.63 ( 0.00%) 2.54 * 3.47%*
Amean elsp-NUMA01 517.17 ( 0.00%) 526.34 * -1.77%*
Amean elsp-NUMA01_THREADLOCAL 99.92 ( 0.00%) 100.59 * -0.67%*
Amean elsp-NUMA02 15.81 ( 0.00%) 15.72 * 0.59%*
Amean elsp-NUMA02_SMT 13.23 ( 0.00%) 12.89 * 2.53%*
v6.10-rc5 v6.10-rc5
+patch
Duration User 1064010.16 1075416.23
Duration System 3307.64 3104.66
Duration Elapsed 4537.54 4604.73
The SPECcpu remote node access issue disappears with the patch applied.
Link: https://lkml.kernel.org/r/20240827112958.181388-1-yu.c.chen@intel.com
Fixes: fc137c0dda ("sched/numa: enhance vma scanning logic")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Co-developed-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Reported-by: Xiaoping Zhou <xiaoping.zhou@intel.com>
Reviewed-and-tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: "Chen, Tim C" <tim.c.chen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The aim is to simplify and making the vm_area_alloc_pages()
function less confusing as it became more clogged nowadays:
- eliminate a "bulk_gfp" variable and do not overwrite a gfp
flag for bulk allocator;
- drop __GFP_NOFAIL flag for high-order-page requests on upper
layer. It becomes less spread between levels when it comes to
__GFP_NOFAIL allocations;
- add a comment about a fallback path if high-order attempt is
unsuccessful because for such cases __GFP_NOFAIL is dropped;
- fix a typo in a commit message.
Link: https://lkml.kernel.org/r/20240827190916.34242-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In commit 714965ca82 ("mm/mmap: start distinguishing if vma can be
removed in mergeability test") we relaxed the VMA merge rules for VMAs
possessing a vm_ops->close() hook, permitting this operation in instances
where we wouldn't delete the VMA as part of the merge operation.
This was later corrected in commit fc0c8f9089 ("mm, mmap: fix
vma_merge() case 7 with vma_ops->close") to account for a subtle case that
the previous commit had not taken into account.
In both instances, we first rely on is_mergeable_vma() to determine
whether we might be dealing with a VMA that might be removed, taking
advantage of the fact that a 'previous' VMA will never be deleted, only
VMAs that follow it.
The second patch corrects the instance where a merge of the previous VMA
into a subsequent one did not correctly check whether the subsequent VMA
had a vm_ops->close() handler.
Both changes prevent merge cases that are actually permissible (for
instance a merge of a VMA into a following VMA with a vm_ops->close(), but
with no previous VMA, which would result in the next VMA being extended,
not deleted).
In addition, both changes fail to consider the case where a VMA that would
otherwise be merged with the previous and next VMA might have
vm_ops->close(), on the assumption that for this to be the case, all three
would have to have the same vma->vm_file to be mergeable and thus the same
vm_ops.
And in addition both changes operate at 50,000 feet, trying to guess
whether a VMA will be deleted.
As we have majorly refactored the VMA merge operation and de-duplicated
code to the point where we know precisely where deletions will occur, this
patch removes the aforementioned checks altogether and instead explicitly
checks whether a VMA will be deleted.
In cases where a reduced merge is still possible (where we merge both
previous and next VMA but the next VMA has a vm_ops->close hook, meaning
we could just merge the previous and current VMA), we do so, otherwise the
merge is not permitted.
We take advantage of our userland testing to assert that this functions
correctly - replacing the previous limited vm_ops->close() tests with
tests for every single case where we delete a VMA.
We also update all testing for both new and modified VMAs to set
vma->vm_ops->close() in every single instance where this would not prevent
the merge, to assert that we never do so.
Link: https://lkml.kernel.org/r/9f96b8cfeef3d14afabddac3d6144afdfbef2e22.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The existing vma_merge() function is no longer required to handle what
were previously referred to as cases 1-3 (i.e. the merging of a new VMA),
as this is now handled by vma_merge_new_vma().
Additionally, simplify the convoluted control flow of the original,
maintaining identical logic only expressed more clearly and doing away
with a complicated set of cases, rather logically examining each possible
outcome - merging of both the previous and subsequent VMA, merging of the
previous VMA and merging of the subsequent VMA alone.
We now utilise the previously implemented commit_merge() function to share
logic with vma_expand() de-duplicating code and providing less surface
area for bugs and confusion. In order to do so, we adjust this function
to accept parameters specific to merging existing ranges.
Link: https://lkml.kernel.org/r/2cf6016b7bfcc4965fc3cde10827560c42e4f12c.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull the part of vma_expand() which actually commits the merge operation,
that is inserts it into the maple tree and sets the VMA's vma->vm_start
and vma->vm_end parameters, into its own function.
We implement only the parts needed for vma_expand() which now as a result
of previous work is also the means by which new VMA ranges are merged.
The next commit in the series will implement merging of existing ranges
which will extend commit_merge() to accommodate this case and result in
all merges using this common code.
Link: https://lkml.kernel.org/r/7b985a20dfa549e3c370cd274d732b64c44f6dbd.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now we have abstracted merge behaviour for new VMA ranges, we are able to
render vma_prepare(), init_vma_prep(), vma_complete(),
can_vma_merge_before() and can_vma_merge_after() static and internal to
vma.c.
These are internal implementation details of kernel VMA manipulation and
merging mechanisms and thus should not be exposed. This also renders the
functions userland testable.
Link: https://lkml.kernel.org/r/7f7f1c34ce10405a6aab2714c505af3cf41b7851.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Abstract vma_merge_new_vma() to use vma_merge_struct and rename the
resultant function vma_merge_new_range() to be clear what the purpose of
this function is - a new VMA is desired in the specified range, and we
wish to see if it is possible to 'merge' surrounding VMAs into this range
rather than having to allocate a new VMA.
Note that this function uses vma_extend() exclusively, so adopts its
requirement that the iterator point at or before the gap. We add an
assert to this effect.
This is as opposed to vma_merge_existing_range(), which will be introduced
in a subsequent commit, and provide the same functionality for cases in
which we are modifying an existing VMA.
In mmap_region() and do_brk_flags() we open code scenarios where we prefer
to use vma_expand() rather than invoke a full vma_merge() operation.
Abstract this logic and eliminate all of the open-coding, and also use the
same logic for all cases where we add new VMAs to, rather than ultimately
use vma_merge(), rather use vma_expand().
Doing so removes duplication and simplifies VMA merging in all such cases,
laying the ground for us to eliminate the merging of new VMAs in
vma_merge() altogether.
Also add the ability for the vmg to track state, and able to report
errors, allowing for us to differentiate a failed merge from an inability
to allocate memory in callers.
This makes it far easier to understand what is happening in these cases
avoiding confusion, bugs and allowing for future optimisation.
Also introduce vma_iter_next_rewind() to allow for retrieval of the next,
and (optionally) the prev VMA, rewinding to the start of the previous gap.
Introduce are_anon_vmas_compatible() to abstract individual VMA anon_vma
comparison for the case of merging on both sides where the anon_vma of the
VMA being merged maybe compatible with prev and next, but prev and next's
anon_vma's may not be compatible with each other.
Finally also introduce can_vma_merge_left() / can_vma_merge_right() to
check adjacent VMA compatibility and that they are indeed adjacent.
Link: https://lkml.kernel.org/r/49d37c0769b6b9dc03b27fe4d059173832556392.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Tested-by: Mark Brown <broonie@kernel.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The purpose of the vmg is to thread merge state through functions and
avoid egregious parameter lists. We expand this to vma_expand(), which is
used for a number of merge cases.
Accordingly, adjust its callers, mmap_region() and relocate_vma_down(), to
use a vmg.
An added purpose of this change is the ability in a future commit to
perform all new VMA range merging using vma_expand().
Link: https://lkml.kernel.org/r/4bc8c9dbc9ca52452ef8e587b28fe555854ceb38.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Both can_vma_merge_before() and can_vma_merge_after() are invoked after
checking for compatible VMA NUMA policy, we can simply move this to
is_mergeable_vma() and abstract this altogether.
In mmap_region() we set vmg->policy to NULL, so the policy comparisons
checked in can_vma_merge_before() and can_vma_merge_after() are exactly
equivalent to !vma_policy(vmg.next) and !vma_policy(vmg.prev).
Equally, in do_brk_flags(), vmg->policy is NULL, so the
can_vma_merge_after() is checking !vma_policy(vma), as we set vmg.prev to
vma.
In vma_merge(), we compare prev and next policies with vmg->policy before
checking can_vma_merge_after() and can_vma_merge_before() respectively,
which this patch causes to be checked in precisely the same way.
This therefore maintains precisely the same logic as before, only now
abstracted into is_mergeable_vma().
Link: https://lkml.kernel.org/r/0dbff286d9c4988333bc6f4ff3734cb95dd5410a.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rather than passing around huge numbers of parameters to numerous helper
functions, abstract them into a single struct that we thread through the
operation, the vma_merge_struct ('vmg').
Adjust vma_merge() and vma_modify() to accept this parameter, as well as
predicate functions can_vma_merge_before(), can_vma_merge_after(), and the
vma_modify_...() helper functions.
Also introduce VMG_STATE() and VMG_VMA_STATE() helper macros to allow for
easy vmg declaration.
We additionally remove the requirement that vma_merge() is passed a VMA
object representing the candidate new VMA. Previously it used this to
obtain the mm_struct, file and anon_vma properties of the proposed range
(a rather confusing state of affairs), which are now provided by the vmg
directly.
We also remove the pgoff calculation previously performed vma_modify(),
and instead calculate this in VMG_VMA_STATE() via the vma_pgoff_offset()
helper.
Link: https://lkml.kernel.org/r/a955aad09d81329f6fbeb636b2dd10cde7b73dab.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add a variety of VMA merge unit tests to assert that the behaviour of VMA
merge is correct at an abstract level and VMAs are merged or not merged as
expected.
These are intentionally added _before_ we start refactoring vma_merge() in
order that we can continually assert correctness throughout the rest of
the series.
In order to reduce churn going forward, we backport the vma_merge_struct
data type to the test code which we introduce and use in a future commit,
and add wrappers around the merge new and existing VMA cases.
Link: https://lkml.kernel.org/r/1c7a0b43cfad2c511a6b1b52f3507696478ff51a.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm: remove vma_merge()", v3.
The infamous vma_merge() function has been the cause of a great deal of
pain, bugs and confusion for a very long time.
It is subtle, contains many corner cases, tries to do far too much and is
as a result very fragile.
The fact that the function requires there to be a numbering system to
cover each possible eventuality with references to each in the many
branches of its implementation as to which case you are looking at speaks
to all this.
Some of this complexity is inherent - unfortunately there is no getting
away from the need to figure out precisely how to execute the merge,
whether we need to remove VMAs, whether it is safe to do so, what
constitutes a mergeable VMA and so on.
However, a lot of the complexity is not inherent but instead a product of
the function's 'organic' development.
Liam has gone to great lengths to improve the situation as a part of his
maple tree implementation, greatly improving the readability of the code,
and Vlastimil and myself have additionally gone to lengths to try to
improve things further.
However, with the availability of userland VMA testing, it now becomes
possible to perform a rather more significant refactoring while
maintaining confidence in its correct operation.
An attempt was previously made by Vlastimil [0] to eliminate vma_merge(),
however it was rather - brutal - and an astute reader might refer to the
date of that patch for insight as to its intent.
This series instead divides merge operations into two natural kinds -
merges which occur when a NEW vma is being added to the address space, and
merges which occur when a vma is being MODIFIED.
Happily, the vma_expand() function introduced by Liam, which has the
capacity for also deleting a subsequent VMA, covers each of the NEW vma
cases.
By abstracting the actual final commit of changes to a VMA to its own
function, commit_merge() and writing a wrapper around vma_expand() for new
VMA cases vma_merge_new_range(), we can avoid having to use vma_merge()
for these instances altogether.
By doing so we are also able to then de-duplicate all existing merge logic
in mmap_region() and do_brk_flags() and have everything invoke this new
function, so we universally take the same approach to merging new VMAs.
Having done so, we can then completely rework vma_merge() into
vma_merge_existing_range() and use this for the instances where a merge is
proposed for a region of an existing VMA.
This eliminates vma_merge() and its numbered cases and instead divides
things into logical cases - merge both, merge left, merge right (the
latter 2 being either partial or full merges).
The code is heavily annotated with ASCII diagrams and greatly simplified
in comparison to the existing vma_merge() function.
Having made this change, we take the opportunity to address an issue with
merging VMAs possessing a vm_ops->close() hook - commit 714965ca82
("mm/mmap: start distinguishing if vma can be removed in mergeability
test") and commit fc0c8f9089 ("mm, mmap: fix vma_merge() case 7 with
vma_ops->close") make efforts to relax how we handle these, making
assumptions about which VMAs might end up deleted (and thus, if possessing
a vm_ops->close() hook, cannot be).
This refactor means we do not need to guess, so instead explicitly only
disallow merge in instances where a VMA with a vm_ops->close() hook would
be deleted (and try a smaller merge in cases where this is possible).
In addition to these changes, we introduce a new vma_merge_struct
abstraction to allow VMA merge state to be threaded through the operation
neatly.
There is heavy unit testing provided for all merge functionality, added
prior to the refactoring, allowing for before/after testing.
The vm_ops->close() change also introduces exhaustive testing to
demonstrate that this functions as expected, and in addition to this the
reproduction code from commit fc0c8f9089 ("mm, mmap: fix vma_merge()
case 7 with vma_ops->close") was tested and confirmed passing.
[0]:https://lore.kernel.org/linux-mm/20240401192623.18575-2-vbabka@suse.cz/
This patch (of 10):
Have vma.o depend on its source dependencies explicitly, as previously
these were simply being ignored as existing object files were up to date.
This now correctly re-triggers the build if mm/ source is changed as well
as local source code.
Also set clean as a phony rule.
Link: https://lkml.kernel.org/r/cover.1725040657.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/e3ea58f08364ae5432c9a074de0195a7c7e0b04a.1725040657.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The comment has been outdated since 6b73cff239 ("mm: change munmap
splitting order and move_vma()"). The move_vma() was altered to fix the
fragile state of the accounting since then.
Link: https://lkml.kernel.org/r/20240830040101.822209-21-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The may_expand_vm() check requires the count of the pages within the
munmap range. Since this is needed for accounting and obtained later, the
reodering of ma_expand_vm() to later in the call stack, after the vma
munmap struct (vms) is initialised and the gather stage is potentially
run, will allow for a single loop over the vmas. The gather sage does not
commit any work and so everything can be undone in the case of a failure.
The MAP_FIXED page count is available after the vms_gather_munmap_vmas()
call, so use it instead of looping over the vmas twice.
Link: https://lkml.kernel.org/r/20240830040101.822209-20-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The do_vma_munmap() wrapper existed for callers that didn't have a vma
iterator and needed to check the vma mseal status prior to calling the
underlying munmap(). All callers now use a vma iterator and since the
mseal check has been moved to do_vmi_align_munmap() and the vmas are
aligned, this function can just be called instead.
do_vmi_align_munmap() can no longer be static as ipc/shm is using it and
it is exported via the mm.h header.
Link: https://lkml.kernel.org/r/20240830040101.822209-19-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Change from nr_pages variable to vms.nr_accounted for the charged pages
calculation. This is necessary for a future patch.
This also avoids checking security_vm_enough_memory_mm() if the amount of
memory won't change.
Link: https://lkml.kernel.org/r/20240830040101.822209-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Paul Moore <paul@paul-moore.com> [LSM]
Cc: Kees Cook <kees@kernel.org>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Instead of shifting the length by PAGE_SIZE, use PHYS_PFN. Also use the
existing local variable everywhere instead of some of the time.
Link: https://lkml.kernel.org/r/20240830040101.822209-17-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Bert Karwatzki <spasswolf@web.de>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
