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| author | Lorenzo Stoakes <ljs@kernel.org> | 2026-06-19 12:28:51 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-06-21 11:37:38 -0700 |
| commit | 13a1e1a618858407fa12c391f664ea750651f6b2 (patch) | |
| tree | a37196f4677422ebfe2ab1a426a4a0583b14bfba /mm | |
| parent | 44238b122ae834ac52748e59809a139a2cb8409b (diff) | |
| download | linux-13a1e1a618858407fa12c391f664ea750651f6b2.tar.gz linux-13a1e1a618858407fa12c391f664ea750651f6b2.zip | |
Revert "mm: limit filemap_fault readahead to VMA boundaries"
This reverts commit 7b32f64bc512b40b268776c5ac4d354b325b3197.
This patch caused a significant performance regression, so revert it, and
we can determine whether the approach is sensible or not moving forwards,
and if so how to avoid this.
There was a merge conflict with commit de97ae6222c1 ("mm/readahead: no
PG_readahead on EOF"), care was taken to ensure that the revert retained
the behaviour of this patch and cleanly reverts commit 7b32f64bc512 ("mm:
limit filemap_fault readahead to VMA boundaries") only.
Link: https://lore.kernel.org/20260619112852.104213-1-ljs@kernel.org
Fixes: 7b32f64bc512 ("mm: limit filemap_fault readahead to VMA boundaries")
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202606181547.617a6967-lkp@intel.com
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/filemap.c | 4 | ||||
| -rw-r--r-- | mm/readahead.c | 6 |
2 files changed, 1 insertions, 9 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index dc3a0e960b9f..17a64837597c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3312,8 +3312,6 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf) unsigned int thp_order = 0; unsigned short mmap_miss; - ractl._max_index = vmf->vma->vm_pgoff + vma_pages(vmf->vma) - 1; - /* Use the readahead code, even if readahead is disabled */ if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && (vm_flags & VM_HUGEPAGE)) { /* @@ -3409,7 +3407,6 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf) * mmap read-around */ ra->start = max_t(long, 0, vmf->pgoff - ra->ra_pages / 2); - ra->start = max(ra->start, vmf->vma->vm_pgoff); ra->size = ra->ra_pages; ra->async_size = ra->ra_pages / 4; ra->order = 0; @@ -3457,7 +3454,6 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf, } if (folio_test_readahead(folio)) { - ractl._max_index = vmf->vma->vm_pgoff + vma_pages(vmf->vma) - 1; fpin = maybe_unlock_mmap_for_io(vmf, fpin); page_cache_async_ra(&ractl, folio, ra->ra_pages); } diff --git a/mm/readahead.c b/mm/readahead.c index 38ce16e3fcbd..558c92957518 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -335,8 +335,6 @@ static void do_page_cache_ra(struct readahead_control *ractl, return; end_index = (isize - 1) >> PAGE_SHIFT; - if (end_index > ractl->_max_index) - end_index = ractl->_max_index; if (index > end_index) return; /* Don't read past the page containing the last byte of the file */ @@ -487,7 +485,7 @@ void page_cache_ra_order(struct readahead_control *ractl, pgoff_t start = readahead_index(ractl); pgoff_t index = start; unsigned int min_order = mapping_min_folio_order(mapping); - pgoff_t limit; + pgoff_t limit = (i_size_read(mapping->host) - 1) >> PAGE_SHIFT; pgoff_t mark; unsigned int nofs; int err = 0; @@ -500,8 +498,6 @@ void page_cache_ra_order(struct readahead_control *ractl, goto fallback; } - limit = (i_size_read(mapping->host) - 1) >> PAGE_SHIFT; - limit = min(limit, ractl->_max_index); if (limit > index + ra->size - 1) { limit = index + ra->size - 1; mark = index + ra->size - ra->async_size; |