diff options
| author | Jens Axboe <axboe@kernel.dk> | 2024-12-20 08:47:50 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-01-25 20:22:44 -0800 |
| commit | d94d23fdd7529f1f3218235d1e0a69e9856907b7 (patch) | |
| tree | 4d141ebef762478f35f56094ba9ce7b2da852598 /mm/filemap.c | |
| parent | 1d4457576570627e1702614bc060b55d95b85e39 (diff) | |
mm: add FGP_DONTCACHE folio creation flag
Callers can pass this in for uncached folio creation, in which case if a
folio is newly created it gets marked as uncached. If a folio exists for
this index and lookup succeeds, then it will not get marked as uncached.
If an !uncached lookup finds a cached folio, clear the flag. For that
case, there are competeting uncached and cached users of the folio, and it
should not get pruned.
Link: https://lkml.kernel.org/r/20241220154831.1086649-13-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 0aa3861aed45..279959cf9300 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1973,6 +1973,8 @@ no_page: /* Init accessed so avoid atomic mark_page_accessed later */ if (fgp_flags & FGP_ACCESSED) __folio_set_referenced(folio); + if (fgp_flags & FGP_DONTCACHE) + __folio_set_dropbehind(folio); err = filemap_add_folio(mapping, folio, index, gfp); if (!err) @@ -1995,6 +1997,9 @@ no_page: if (!folio) return ERR_PTR(-ENOENT); + /* not an uncached lookup, clear uncached if set */ + if (folio_test_dropbehind(folio) && !(fgp_flags & FGP_DONTCACHE)) + folio_clear_dropbehind(folio); return folio; } EXPORT_SYMBOL(__filemap_get_folio); |