The quilt patch titled Subject: mm: optimize invalidation of shadow entries has been removed from the -mm tree. Its filename was mm-optimize-invalidation-of-shadow-entries.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Shakeel Butt <shakeel.butt@xxxxxxxxx> Subject: mm: optimize invalidation of shadow entries Date: Wed, 25 Sep 2024 15:47:16 -0700 The kernel invalidates the page cache in batches of PAGEVEC_SIZE. For each batch, it traverses the page cache tree and collects the entries (folio and shadow entries) in the struct folio_batch. For the shadow entries present in the folio_batch, it has to traverse the page cache tree for each individual entry to remove them. This patch optimize this by removing them in a single tree traversal. To evaluate the changes, we created 200GiB file on a fuse fs and in a memcg. We created the shadow entries by triggering reclaim through memory.reclaim in that specific memcg and measure the simple fadvise(DONTNEED) operation. # time xfs_io -c 'fadvise -d 0 ${file_size}' file time (sec) Without 5.12 +- 0.061 With-patch 4.19 +- 0.086 (18.16% decrease) Link: https://lkml.kernel.org/r/20240925224716.2904498-3-shakeel.butt@xxxxxxxxx Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx> Cc: Chris Mason <clm@xxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Omar Sandoval <osandov@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/truncate.c | 46 ++++++++++++++++++---------------------------- 1 file changed, 18 insertions(+), 28 deletions(-) --- a/mm/truncate.c~mm-optimize-invalidation-of-shadow-entries +++ a/mm/truncate.c @@ -23,42 +23,28 @@ #include <linux/rmap.h> #include "internal.h" -/* - * Regular page slots are stabilized by the page lock even without the tree - * itself locked. These unlocked entries need verification under the tree - * lock. - */ -static inline void __clear_shadow_entry(struct address_space *mapping, - pgoff_t index, void *entry) -{ - XA_STATE(xas, &mapping->i_pages, index); - - xas_set_update(&xas, workingset_update_node); - if (xas_load(&xas) != entry) - return; - xas_store(&xas, NULL); -} - static void clear_shadow_entries(struct address_space *mapping, - struct folio_batch *fbatch, pgoff_t *indices) + unsigned long start, unsigned long max) { - int i; + XA_STATE(xas, &mapping->i_pages, start); + struct folio *folio; /* Handled by shmem itself, or for DAX we do nothing. */ if (shmem_mapping(mapping) || dax_mapping(mapping)) return; - spin_lock(&mapping->host->i_lock); - xa_lock_irq(&mapping->i_pages); + xas_set_update(&xas, workingset_update_node); - for (i = 0; i < folio_batch_count(fbatch); i++) { - struct folio *folio = fbatch->folios[i]; + spin_lock(&mapping->host->i_lock); + xas_lock_irq(&xas); + /* Clear all shadow entries from start to max */ + xas_for_each(&xas, folio, max) { if (xa_is_value(folio)) - __clear_shadow_entry(mapping, indices[i], folio); + xas_store(&xas, NULL); } - xa_unlock_irq(&mapping->i_pages); + xas_unlock_irq(&xas); if (mapping_shrinkable(mapping)) inode_add_lru(mapping->host); spin_unlock(&mapping->host->i_lock); @@ -481,7 +467,9 @@ unsigned long mapping_try_invalidate(str folio_batch_init(&fbatch); while (find_lock_entries(mapping, &index, end, &fbatch, indices)) { - for (i = 0; i < folio_batch_count(&fbatch); i++) { + int nr = folio_batch_count(&fbatch); + + for (i = 0; i < nr; i++) { struct folio *folio = fbatch.folios[i]; /* We rely upon deletion not changing folio->index */ @@ -508,7 +496,7 @@ unsigned long mapping_try_invalidate(str } if (xa_has_values) - clear_shadow_entries(mapping, &fbatch, indices); + clear_shadow_entries(mapping, indices[0], indices[nr-1]); folio_batch_remove_exceptionals(&fbatch); folio_batch_release(&fbatch); @@ -612,7 +600,9 @@ int invalidate_inode_pages2_range(struct folio_batch_init(&fbatch); index = start; while (find_get_entries(mapping, &index, end, &fbatch, indices)) { - for (i = 0; i < folio_batch_count(&fbatch); i++) { + int nr = folio_batch_count(&fbatch); + + for (i = 0; i < nr; i++) { struct folio *folio = fbatch.folios[i]; /* We rely upon deletion not changing folio->index */ @@ -658,7 +648,7 @@ int invalidate_inode_pages2_range(struct } if (xa_has_values) - clear_shadow_entries(mapping, &fbatch, indices); + clear_shadow_entries(mapping, indices[0], indices[nr-1]); folio_batch_remove_exceptionals(&fbatch); folio_batch_release(&fbatch); _ Patches currently in -mm which might be from shakeel.butt@xxxxxxxxx are