diff options
| author | Matthew Wilcox (Oracle) | 2021-05-04 18:32:45 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2021-05-05 11:27:19 -0700 |
| commit | 7716506adac4664793a9d6d3dfa31ffddfa98714 (patch) | |
| tree | ec099a414e8120e3e68e2e6022eed8fa6fff5a3b /include/linux | |
| parent | 4d75136be8bf3ae01b0bc3e725b2cdc921e103bd (diff) | |
mm: introduce and use mapping_empty()
Patch series "Remove nrexceptional tracking", v2.
We actually use nrexceptional for very little these days. It's a minor
pain to keep in sync with nrpages, but the pain becomes much bigger with
the THP patches because we don't know how many indices a shadow entry
occupies. It's easier to just remove it than keep it accurate.
Also, we save 8 bytes per inode which is nothing to sneeze at; on my
laptop, it would improve shmem_inode_cache from 22 to 23 objects per
16kB, and inode_cache from 26 to 27 objects. Combined, that saves
a megabyte of memory from a combined usage of 25MB for both caches.
Unfortunately, ext4 doesn't cross a magic boundary, so it doesn't save
any memory for ext4.
This patch (of 4):
Instead of checking the two counters (nrpages and nrexceptional), we can
just check whether i_pages is empty.
Link: https://lkml.kernel.org/r/20201026151849.24232-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20201026151849.24232-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pagemap.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 469fa7ffcf96..a4bd41128bf3 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -18,6 +18,11 @@ struct pagevec; +static inline bool mapping_empty(struct address_space *mapping) +{ + return xa_empty(&mapping->i_pages); +} + /* * Bits in mapping->flags. */ |