[PATCH 04/13] i915: Convert shmem_sg_free_table() to use a folio_batch
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2023-06-21 16:46:47
Also in:
dri-devel, intel-gfx, linux-fsdevel, linux-mm, linux-nfs, lkml
Subsystem:
drm drivers, intel drm i915 driver (meteor lake, dg2 and older excluding poulsbo, moorestown and derivative), the rest · Maintainers:
David Airlie, Simona Vetter, Jani Nikula, Joonas Lahtinen, Rodrigo Vivi, Tvrtko Ursulin, Linus Torvalds
Remove a few hidden compound_head() calls by converting the returned page to a folio once and using the folio APIs. We also only increment the refcount on the folio once instead of once for each page. Ideally, we would have a for_each_sgt_folio macro, but until then this will do. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 55 +++++++++++++---------- 1 file changed, 31 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
index 33d5d5178103..8f1633c3fb93 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c@@ -19,13 +19,13 @@ #include "i915_trace.h" /* - * Move pages to appropriate lru and release the pagevec, decrementing the - * ref count of those pages. + * Move folios to appropriate lru and release the batch, decrementing the + * ref count of those folios. */ -static void check_release_pagevec(struct pagevec *pvec) +static void check_release_folio_batch(struct folio_batch *fbatch) { - check_move_unevictable_pages(pvec); - __pagevec_release(pvec); + check_move_unevictable_folios(fbatch); + __folio_batch_release(fbatch); cond_resched(); }
@@ -33,24 +33,29 @@ void shmem_sg_free_table(struct sg_table *st, struct address_space *mapping, bool dirty, bool backup) { struct sgt_iter sgt_iter; - struct pagevec pvec; + struct folio_batch fbatch; + struct folio *last = NULL; struct page *page; mapping_clear_unevictable(mapping); - pagevec_init(&pvec); + folio_batch_init(&fbatch); for_each_sgt_page(page, sgt_iter, st) { - if (dirty) - set_page_dirty(page); + struct folio *folio = page_folio(page); + if (folio == last) + continue; + last = folio; + if (dirty) + folio_mark_dirty(folio); if (backup) - mark_page_accessed(page); + folio_mark_accessed(folio); - if (!pagevec_add(&pvec, page)) - check_release_pagevec(&pvec); + if (!folio_batch_add(&fbatch, folio)) + check_release_folio_batch(&fbatch); } - if (pagevec_count(&pvec)) - check_release_pagevec(&pvec); + if (fbatch.nr) + check_release_folio_batch(&fbatch); sg_free_table(st); }
@@ -63,8 +68,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, unsigned int page_count; /* restricted by sg_alloc_table */ unsigned long i; struct scatterlist *sg; - struct page *page; - unsigned long last_pfn = 0; /* suppress gcc warning */ + unsigned long next_pfn = 0; /* suppress gcc warning */ gfp_t noreclaim; int ret;
@@ -95,6 +99,7 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, sg = st->sgl; st->nents = 0; for (i = 0; i < page_count; i++) { + struct folio *folio; const unsigned int shrink[] = { I915_SHRINK_BOUND | I915_SHRINK_UNBOUND, 0,
@@ -103,12 +108,12 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, do { cond_resched(); - page = shmem_read_mapping_page_gfp(mapping, i, gfp); - if (!IS_ERR(page)) + folio = shmem_read_folio_gfp(mapping, i, gfp); + if (!IS_ERR(folio)) break; if (!*s) { - ret = PTR_ERR(page); + ret = PTR_ERR(folio); goto err_sg; }
@@ -147,19 +152,21 @@ int shmem_sg_alloc_table(struct drm_i915_private *i915, struct sg_table *st, if (!i || sg->length >= max_segment || - page_to_pfn(page) != last_pfn + 1) { + folio_pfn(folio) != next_pfn) { if (i) sg = sg_next(sg); st->nents++; - sg_set_page(sg, page, PAGE_SIZE, 0); + sg_set_folio(sg, folio, folio_size(folio), 0); } else { - sg->length += PAGE_SIZE; + /* XXX: could overflow? */ + sg->length += folio_size(folio); } - last_pfn = page_to_pfn(page); + next_pfn = folio_pfn(folio) + folio_nr_pages(folio); + i += folio_nr_pages(folio) - 1; /* Check that the i965g/gm workaround works. */ - GEM_BUG_ON(gfp & __GFP_DMA32 && last_pfn >= 0x00100000UL); + GEM_BUG_ON(gfp & __GFP_DMA32 && next_pfn >= 0x00100000UL); } if (sg) /* loop terminated early; short sg table */ sg_mark_end(sg);
--
2.39.2