dddb44ffa0
Patch series "memcg: OOM log improvements", v2. This short patch series brings back some cgroup v1 stats in OOM logs that were unnecessarily changed before. It also makes memcg OOM logs less reliant on printk() internals. This patch (of 2): Commitc8713d0b23("mm: memcontrol: dump memory.stat during cgroup OOM") made sure we dump all the stats in memory.stat during a cgroup OOM, but it also introduced a slight behavioral change. The code used to print the non-hierarchical v1 cgroup stats for the entire cgroup subtree, now it only prints the v2 cgroup stats for the cgroup under OOM. For cgroup v1 users, this introduces a few problems: (a) The non-hierarchical stats of the memcg under OOM are no longer shown. (b) A couple of v1-only stats (e.g. pgpgin, pgpgout) are no longer shown. (c) We show the list of cgroup v2 stats, even in cgroup v1. This list of stats is not tracked with v1 in mind. While most of the stats seem to be working on v1, there may be some stats that are not fully or correctly tracked. Although OOM log is not set in stone, we should not change it for no reason. When upgrading the kernel version to a version including commitc8713d0b23("mm: memcontrol: dump memory.stat during cgroup OOM"), these behavioral changes are noticed in cgroup v1. The fix is simple. Commitc8713d0b23("mm: memcontrol: dump memory.stat during cgroup OOM") separated stats formatting from stats display for v2, to reuse the stats formatting in the OOM logs. Do the same for v1. Move the v2 specific formatting from memory_stat_format() to memcg_stat_format(), add memcg1_stat_format() for v1, and make memory_stat_format() select between them based on cgroup version. Since memory_stat_show() now works for both v1 & v2, drop memcg_stat_show(). Link: https://lkml.kernel.org/r/20230428132406.2540811-1-yosryahmed@google.com Link: https://lkml.kernel.org/r/20230428132406.2540811-3-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Petr Mladek <pmladek@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.