Commit 9f08ebc3 authored by David Howells's avatar David Howells
Browse files

fscache, cachefiles: Display stat of culling events 



Add a stat counter of culling events whereby the cache backend culls a file
to make space (when asked by cachefilesd in this case) and display in
/proc/fs/fscache/stats.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819654165.215744.3797804661644212436.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906961387.143852.9291157239960289090.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967168266.1823006.14436200166581605746.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021567619.640689.4339228906248763197.stgit@warthog.procyon.org.uk/ # v4
parent 3929eca7

fs/cachefiles/namei.c

+1 −0
Original line number Diff line number Diff line
@@ -805,6 +805,7 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, 
	if (ret < 0)

		goto error;



	fscache_count_culled();

	dput(victim);

	_leave(" = 0");

	return 0;

fs/fscache/stats.c

+5 −2
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ atomic_t fscache_n_no_write_space; 
EXPORT_SYMBOL(fscache_n_no_write_space);

atomic_t fscache_n_no_create_space;

EXPORT_SYMBOL(fscache_n_no_create_space);

atomic_t fscache_n_culled;

EXPORT_SYMBOL(fscache_n_culled);



/*

 * display the general statistics
@@ -86,9 +88,10 @@ int fscache_stats_show(struct seq_file *m, void *v) 
		   atomic_read(&fscache_n_relinquishes_retire),

		   atomic_read(&fscache_n_relinquishes_dropped));



	seq_printf(m, "NoSpace: nwr=%u ncr=%u\n",

	seq_printf(m, "NoSpace: nwr=%u ncr=%u cull=%u\n",

		   atomic_read(&fscache_n_no_write_space),

		   atomic_read(&fscache_n_no_create_space));

		   atomic_read(&fscache_n_no_create_space),

		   atomic_read(&fscache_n_culled));



	seq_printf(m, "IO     : rd=%u wr=%u\n",

		   atomic_read(&fscache_n_read),

include/linux/fscache-cache.h

+3 −0
Original line number Diff line number Diff line
@@ -188,15 +188,18 @@ extern atomic_t fscache_n_read; 
extern atomic_t fscache_n_write;

extern atomic_t fscache_n_no_write_space;

extern atomic_t fscache_n_no_create_space;

extern atomic_t fscache_n_culled;

#define fscache_count_read() atomic_inc(&fscache_n_read)

#define fscache_count_write() atomic_inc(&fscache_n_write)

#define fscache_count_no_write_space() atomic_inc(&fscache_n_no_write_space)

#define fscache_count_no_create_space() atomic_inc(&fscache_n_no_create_space)

#define fscache_count_culled() atomic_inc(&fscache_n_culled)

#else

#define fscache_count_read() do {} while(0)

#define fscache_count_write() do {} while(0)

#define fscache_count_no_write_space() do {} while(0)

#define fscache_count_no_create_space() do {} while(0)

#define fscache_count_culled() do {} while(0)

#endif



#endif /* _LINUX_FSCACHE_CACHE_H */