When return on an error path, file handle need to be closed
to prevent resource leak
Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Patch series "selftests: vm: a few fixup patches".
This series contains three fixup patches for vm selftests. They are
independent. Please see the patches.
This patch (of 3):
Currently, ksm_tests operates "merge_across_nodes" with NUMA either
enabled or disabled. In a system with NUMA disabled, these operations
will fail and output a misleading report given "merge_across_nodes" does
not exist in sysfs:
----------------------------
running ./ksm_tests -M -p 10
----------------------------
f /sys/kernel/mm/ksm/merge_across_nodes
fopen: No such file or directory
Cannot save default tunables
[FAIL]
----------------------
So check numa_available() before those operations to skip them if NUMA is
disabled.
Link: https://lkml.kernel.org/r/20220521083825.319654-1-patrick.wang.shcn@gmail.com
Link: https://lkml.kernel.org/r/20220521083825.319654-2-patrick.wang.shcn@gmail.com
Signed-off-by: Patrick Wang <patrick.wang.shcn@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add test case of KSM merging time using mostly huge pages
Link: https://lkml.kernel.org/r/20211013044045.360251-1-pedrodemargomes@gmail.com
Signed-off-by: Pedro Demarchi Gomes <pedrodemargomes@gmail.com>
Cc: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since merged pages are copied every time they need to be modified, the
write access time is different between shared and non-shared pages. Add
ksm_cow_time() function which evaluates latency of these COW breaks.
First, 4000 pages are allocated and the time, required to modify 1 byte in
every other page, is measured. After this, the pages are merged into 2000
pairs and in each pair, 1 page is modified (i.e. they are decoupled) to
detect COW breaks. The time needed to break COW of merged pages is then
compared with performance of non-shared pages.
The test is run as follows: ./ksm_tests -C
The output:
Total size: 15 MiB
Not merged pages:
Total time: 0.002185489 s
Average speed: 3202.945 MiB/s
Merged pages:
Total time: 0.004386872 s
Average speed: 1595.670 MiB/s
Link: https://lkml.kernel.org/r/1d03ee0d1b341959d4b61672c6401d498bff5652.1629386192.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "add KSM performance tests", v3.
Extend KSM self tests with a performance benchmark. These tests are not
part of regular regression testing, as they are mainly intended to be used
by developers making changes to the memory management subsystem.
This patch (of 2):
Add ksm_merge_time() function to determine speed and time needed for
merging. The total spent time is shown in seconds while speed is in
MiB/s. User must specify the size of duplicated memory area (in MiB)
before running the test.
The test is run as follows: ./ksm_tests -P -s 100
The output:
Total size: 100 MiB
Total time: 0.201106786 s
Average speed: 497.248 MiB/s
Link: https://lkml.kernel.org/r/cover.1629386192.git.zhansayabagdaulet@gmail.com
Link: https://lkml.kernel.org/r/318b946ac80cc9205c89d0962048378f7ce0705b.1629386192.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add check_ksm_numa_merge() function to test that pages in different NUMA
nodes are being handled properly. First, two duplicate pages are
allocated in two separate NUMA nodes using the libnuma library. Since
there is one unique page in each node, with merge_across_nodes = 0, there
won't be any shared pages. If merge_across_nodes is set to 1, the pages
will be treated as usual duplicate pages and will be merged. If NUMA
config is not enabled or the number of NUMA nodes is less than two, then
the test is skipped. The test is run as follows: ./ksm_tests -N
Link: https://lkml.kernel.org/r/071c17b5b04ebb0dfeba137acc495e5dd9d2a719.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add check_ksm_zero_page_merge() function to test that empty pages are
being handled properly. For this, several zero pages are allocated and
merged using madvise. If use_zero_pages is enabled, the pages must be
shared with the special kernel zero pages; otherwise, they are merged as
usual duplicate pages. The test is run as follows: ./ksm_tests -Z
Link: https://lkml.kernel.org/r/6d0caab00d4bdccf5e3791cb95cf6dfd5eb85e45.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add check_ksm_unmerge() function to verify that KSM is properly unmerging
shared pages. For this, two duplicate pages are merged first and then
their contents are modified. Since they are not identical anymore, the
pages must be unmerged and the number of merged pages has to be 0. The
test is run as follows: ./ksm_tests -U
Link: https://lkml.kernel.org/r/c0f55420440d704d5b094275b4365aa1b2ad46b5.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "add KSM selftests".
Introduce selftests to validate the functionality of KSM. The tests are
run on private anonymous pages. Since some KSM tunables are modified,
their starting values are saved and restored after testing. At the start,
run is set to 2 to ensure that only test pages will be merged (we assume
that no applications make madvise syscalls in the background). If KSM
config not enabled, all tests will be skipped.
This patch (of 4):
Add check_ksm_merge() function to check the basic merging feature of KSM.
First, some number of identical pages are allocated and the MADV_MERGEABLE
advice is given to merge these pages. Then, pages_shared and
pages_sharing values are compared with the expected numbers using
assert_ksm_pages_count() function. The number of pages can be changed
using -p option.
Link: https://lkml.kernel.org/r/cover.1626252248.git.zhansayabagdaulet@gmail.com
Link: https://lkml.kernel.org/r/90287685c13300972ea84de93d1f3f900373f9fe.1626252248.git.zhansayabagdaulet@gmail.com
Signed-off-by: Zhansaya Bagdauletkyzy <zhansayabagdaulet@gmail.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
