commit 84055688b6bc075c92a88e2d6c3ad26ab93919f9 upstream.
DAMOS tried regions sysfs directory allocation function
(damon_sysfs_scheme_regions_alloc()) is not handling the memory allocation
failure. In the case, the code will dereference NULL pointer. Handle the
failure to avoid such invalid access.
Link: https://lkml.kernel.org/r/20231106233408.51159-3-sj@kernel.org
Fixes: 9277d0367b ("mm/damon/sysfs-schemes: implement scheme region directory")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [6.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae636ae2bbfd9279f5681dbf320d1da817e52b68 upstream.
DAMON sysfs interface's before_damos_apply callback
(damon_sysfs_before_damos_apply()), which creates the DAMOS tried regions
for each DAMOS action applied region, is not handling the allocation
failure for the sysfs directory data. As a result, NULL pointer
derefeence is possible. Fix it by handling the case.
Link: https://lkml.kernel.org/r/20231106233408.51159-4-sj@kernel.org
Fixes: f1d13cacab ("mm/damon/sysfs: implement DAMOS tried regions update command")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [6.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Extend DAMON sysfs interface to support the DAMON monitoring target based
DAMOS filter. Users can use it via writing 'target' to the filter's
'type' file and specifying the index of the target from the corresponding
DAMON context's monitoring targets list to 'target_idx' sysfs file.
Link: https://lkml.kernel.org/r/20230802214312.110532-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Extend DAMON sysfs interface to support address range based DAMOS filters,
by adding a special keyword for the filter/<N>/type file, namely 'addr',
and two files under filter/<N>/ for specifying the start and the end
addresses of the range, namely 'addr_start' and 'addr_end'.
Link: https://lkml.kernel.org/r/20230802214312.110532-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Using tried_regions/total_bytes file, users can efficiently retrieve the
total size of memory regions having specific access pattern. However,
DAMON sysfs interface in kernel still populates all the infomration on the
tried_regions subdirectories. That means the kernel part overhead for the
construction of tried regions directories still exists. To remove the
overhead, implement yet another command input for 'state' DAMON sysfs
file. Writing the input to the file makes DAMON sysfs interface to update
only the total_bytes file.
Link: https://lkml.kernel.org/r/20230802213222.109841-3-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 "mm/damon/sysfs-schemes: implement DAMOS tried total bytes
file".
The tried_regions directory of DAMON sysfs interface is useful for
retrieving monitoring results snapshot or DAMOS debugging. However, for
common use case that need to monitor only the total size of the scheme
tried regions (e.g., monitoring working set size), the kernel overhead for
directory construction and user overhead for reading the content could be
high if the number of monitoring region is not small. This patchset
implements DAMON sysfs files for efficient support of the use case.
The first patch implements the sysfs file to reduce the user space
overhead, and the second patch implements a command for reducing the
kernel space overhead.
The third patch adds a selftest for the new file, and following two
patches update documents.
[1] https://lore.kernel.org/damon/20230728201817.70602-1-sj@kernel.org/
This patch (of 5):
The tried_regions directory can be used for retrieving the monitoring
results snapshot for regions of specific access pattern, by setting the
scheme's action as 'stat' and the access pattern as required. While the
interface provides every detail of the monitoring results, some use cases
including working set size monitoring requires only the total size of the
regions. For such cases, users should read all the information and
calculate the total size of the regions. However, it could incur high
overhead if the number of regions is high. Add a file for retrieving only
the information, namely 'total_bytes' file. It allows users to get the
total size by reading only the file.
Link: https://lkml.kernel.org/r/20230802213222.109841-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20230802213222.109841-2-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>
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>
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>
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>
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>
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>
Implement region directories under 'tried_regions' directory of each
scheme DAMON sysfs directory. This directory will provide the address
range, the monitored access frequency ('nr_accesses'), and the age of each
DAMON region that corresponding DAMON-based operation scheme has tried to
be applied. Note that this commit doesn't implement the code for filling
the data but only the sysfs directory.
Link: https://lkml.kernel.org/r/20221101220328.95765-4-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>
For efficient and simple query-like DAMON monitoring results readings and
deep level investigations of DAMOS, DAMON kernel API
(include/linux/damon.h) users can use 'before_damos_apply' DAMON callback.
However, DAMON sysfs interface users don't have such option.
Add a directory, namely 'tried_regions', under each scheme directory to
use it as the interface for the purpose. Note that this commit is
implementing only the directory but the data filling.
After the data filling change is made, users will be able to signal DAMON
to fill the directory with the regions that corresponding scheme has tried
to be applied. By setting the access pattern of the scheme, users could
do the efficient query-like monitoring.
Link: https://lkml.kernel.org/r/20221101220328.95765-3-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>
DAMON sysfs interface for 'schemes' directory is implemented using about
one thousand lines of code. It has no strong dependency with other
parts of its file, so split it out to another file for better code
management.
Link: https://lkml.kernel.org/r/20221026225943.100429-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park