Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.
This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.
In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.
The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.
After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40
[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The commit 5c60e89e71 ("NFSv4.2: Fix up an invalid combination of memory
allocation flags") has stripped GFP_KERNEL_ACCOUNT down to GFP_KERNEL,
however, it forgot to remove SLAB_ACCOUNT from kmem_cache allocation.
It means that memory is still limited by kmemcg. This patch also fix a
NULL pointer reference issue [1] reported by NeilBrown.
Link: https://lore.kernel.org/all/164870069595.25542.17292003658915487357@noble.neil.brown.name/ [1]
Fixes: 5c60e89e71 ("NFSv4.2: Fix up an invalid combination of memory allocation flags")
Fixes: 5abc1e37af ("mm: list_lru: allocate list_lru_one only when needed")
Reported-by: NeilBrown <neilb@suse.de>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We should use either GFP_KERNEL or GFP_NOFS, but not both. Also strip
GFP_KERNEL_ACCOUNT down to GFP_KERNEL. This memory is shrinkable, so
does not need to be limited by kmemcg.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
We forgot to unregister the nfs4_xattr_large_entry_shrinker.
That leaves the global list of shrinkers corrupted after unload of the
nfs module, after which possibly unrelated code that calls
register_shrinker() or unregister_shrinker() gets a BUG() with
"supervisor write access in kernel mode".
And similarly for the nfs4_xattr_large_entry_lru.
Reported-by: Kris Karas <bugs-a17@moonlit-rail.com>
Tested-By: Kris Karas <bugs-a17@moonlit-rail.com>
Fixes: 95ad37f90c "NFSv4.2: add client side xattr caching."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
CC: stable@vger.kernel.org
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The list_lru_count() returns the pre node count, but the new xattr
shrinkers are memcg aware, so the shrinkers should return per memcg
count by calling list_lru_shrink_count() instead. Otherwise over-shrink
might be experienced. The problem was spotted by visual code
inspection.
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
Reviewed-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
The hash_lock field of the cache structure was a leftover
of a previous iteration of the code. It is now unused,
so remove it.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Caches should be small enough to discard them inline, so do that
instead of using a work queue.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Implement client side caching for NFSv4.2 extended attributes. The cache
is a per-inode hashtable, with name/value entries. There is one special
entry for the listxattr cache.
NFS inodes have a pointer to a cache structure. The cache structure is
allocated on demand, freed when the cache is invalidated.
Memory shrinkers keep the size in check. Large entries (> PAGE_SIZE)
are collected by a separate shrinker, and freed more aggressively
than others.
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Roman Gushchin