ff48c71c26
At the moment, the amount of memory allocated for stats related structs in the mem_cgroup corresponds to the size of enum node_stat_item. However not all fields in enum node_stat_item have corresponding memcg stats. So, let's use indirection mechanism similar to the one used for memcg vmstats management. For a given x86_64 config, the size of stats with and without patch is: structs size in bytes w/o with struct lruvec_stats 1128 648 struct lruvec_stats_percpu 752 432 struct memcg_vmstats 1832 1352 struct memcg_vmstats_percpu 1280 960 The memory savings are further compounded by the fact that these structs are allocated for each cpu and for each node. To be precise, for each memcg the memory saved would be: Memory saved = ((21 * 3 * NR_NODES) + (21 * 2 * NR_NODES * NR_CPUS) + (21 * 3) + (21 * 2 * NR_CPUS)) * sizeof(long) Where 21 is the number of fields eliminated. Link: https://lkml.kernel.org/r/20240501172617.678560-5-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: T.J. Mercier <tjmercier@google.com> Cc: Yosry Ahmed <yosryahmed@google.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 reStructuredText 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.