Files
linux-cryptodev-2.6/include/linux/zswap.h
Domenico Cerasuolo a65b0e7607 zswap: make shrinking memcg-aware
Currently, we only have a single global LRU for zswap.  This makes it
impossible to perform worload-specific shrinking - an memcg cannot
determine which pages in the pool it owns, and often ends up writing pages
from other memcgs.  This issue has been previously observed in practice
and mitigated by simply disabling memcg-initiated shrinking:

https://lore.kernel.org/all/20230530232435.3097106-1-nphamcs@gmail.com/T/#u

This patch fully resolves the issue by replacing the global zswap LRU
with memcg- and NUMA-specific LRUs, and modify the reclaim logic:

a) When a store attempt hits an memcg limit, it now triggers a
   synchronous reclaim attempt that, if successful, allows the new
   hotter page to be accepted by zswap.
b) If the store attempt instead hits the global zswap limit, it will
   trigger an asynchronous reclaim attempt, in which an memcg is
   selected for reclaim in a round-robin-like fashion.

[nphamcs@gmail.com: use correct function for the onlineness check, use mem_cgroup_iter_break()]
  Link: https://lkml.kernel.org/r/20231205195419.2563217-1-nphamcs@gmail.com
[nphamcs@gmail.com: drop the pool's reference at the end of the writeback step]
  Link: https://lkml.kernel.org/r/20231206030627.4155634-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20231130194023.4102148-4-nphamcs@gmail.com
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Co-developed-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12 10:57:01 -08:00

40 lines
897 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ZSWAP_H
#define _LINUX_ZSWAP_H
#include <linux/types.h>
#include <linux/mm_types.h>
extern u64 zswap_pool_total_size;
extern atomic_t zswap_stored_pages;
#ifdef CONFIG_ZSWAP
bool zswap_store(struct folio *folio);
bool zswap_load(struct folio *folio);
void zswap_invalidate(int type, pgoff_t offset);
void zswap_swapon(int type);
void zswap_swapoff(int type);
void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
#else
static inline bool zswap_store(struct folio *folio)
{
return false;
}
static inline bool zswap_load(struct folio *folio)
{
return false;
}
static inline void zswap_invalidate(int type, pgoff_t offset) {}
static inline void zswap_swapon(int type) {}
static inline void zswap_swapoff(int type) {}
static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
#endif
#endif /* _LINUX_ZSWAP_H */