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authorYin Fengwei <fengwei.yin@intel.com>2023-09-14 16:47:41 +0300
committerAndrew Morton <akpm@linux-foundation.org>2023-09-19 23:21:34 +0300
commitc8be03806738c86521dbf1e0503bc90855fb99a3 (patch)
tree7e40a1758da0534080688ea07639da40f11e59af /mm
parent578d7699e5c2add8c2e9549d9d75dfb56c460cb3 (diff)
downloadlinux-c8be03806738c86521dbf1e0503bc90855fb99a3.tar.xz
filemap: add filemap_map_order0_folio() to handle order0 folio
Kernel test robot reported regressions for several benchmarks [1]. The regression are related with commit: de74976eb65151a2f568e477fc2e0032df5b22b4 ("filemap: add filemap_map_folio_range()") It turned out that function filemap_map_folio_range() brings these regressions when handle folio with order0. Add filemap_map_order0_folio() to handle order0 folio. The benefit come from two perspectives: - the code size is smaller (around 126 bytes) - no loop Testing showed the regressions reported by 0day [1] all are fixed: commit 9f1f5b60e76d44fa: parent commit of de74976eb65151a2 commit fbdf9263a3d7fdbd: latest mm-unstable commit commit 7fbfe2003f84686d: this fixing patch 9f1f5b60e76d44fa fbdf9263a3d7fdbd 7fbfe2003f84686d ---------------- --------------------------- --------------------------- 3843810 -21.4% 3020268 +4.6% 4018708 stress-ng.bad-altstack.ops 64061 -21.4% 50336 +4.6% 66977 stress-ng.bad-altstack.ops_per_sec 1709026 -14.4% 1462102 +2.4% 1750757 stress-ng.fork.ops 28483 -14.4% 24368 +2.4% 29179 stress-ng.fork.ops_per_sec 3685088 -53.6% 1710976 +0.5% 3702454 stress-ng.zombie.ops 56732 -65.3% 19667 +0.7% 57107 stress-ng.zombie.ops_per_sec 61874 -12.1% 54416 +0.4% 62136 vm-scalability.median 13527663 -11.7% 11942117 -0.1% 13513946 vm-scalability.throughput 4.066e+09 -11.7% 3.59e+09 -0.1% 4.061e+09 vm-scalability.workload [1]: https://lore.kernel.org/oe-lkp/72e017b9-deb6-44fa-91d6-716ee2c39cbc@intel.com/T/#m7d2bba30f75a9cee8eab07e5809abd9b3b206c84 Link: https://lkml.kernel.org/r/20230914134741.1937654-1-fengwei.yin@intel.com Fixes: de74976eb65151a2f568e477fc2e0032df5b22b4 ("filemap: add filemap_map_folio_range()") Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202309111556.b2aa3d7a-oliver.sang@intel.com Cc: Feng Tang <feng.tang@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c69
1 files changed, 48 insertions, 21 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 582f5317ff71..4ea4387053e8 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3475,13 +3475,11 @@ skip:
*/
static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
struct folio *folio, unsigned long start,
- unsigned long addr, unsigned int nr_pages)
+ unsigned long addr, unsigned int nr_pages,
+ unsigned int *mmap_miss)
{
vm_fault_t ret = 0;
- struct vm_area_struct *vma = vmf->vma;
- struct file *file = vma->vm_file;
struct page *page = folio_page(folio, start);
- unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss);
unsigned int count = 0;
pte_t *old_ptep = vmf->pte;
@@ -3489,8 +3487,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
if (PageHWPoison(page + count))
goto skip;
- if (mmap_miss > 0)
- mmap_miss--;
+ (*mmap_miss)++;
/*
* NOTE: If there're PTE markers, we'll leave them to be
@@ -3525,7 +3522,35 @@ skip:
}
vmf->pte = old_ptep;
- WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss);
+
+ return ret;
+}
+
+static vm_fault_t filemap_map_order0_folio(struct vm_fault *vmf,
+ struct folio *folio, unsigned long addr,
+ unsigned int *mmap_miss)
+{
+ vm_fault_t ret = 0;
+ struct page *page = &folio->page;
+
+ if (PageHWPoison(page))
+ return ret;
+
+ (*mmap_miss)++;
+
+ /*
+ * NOTE: If there're PTE markers, we'll leave them to be
+ * handled in the specific fault path, and it'll prohibit
+ * the fault-around logic.
+ */
+ if (!pte_none(ptep_get(vmf->pte)))
+ return ret;
+
+ if (vmf->address == addr)
+ ret = VM_FAULT_NOPAGE;
+
+ set_pte_range(vmf, folio, page, 1, addr);
+ folio_ref_inc(folio);
return ret;
}
@@ -3541,7 +3566,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
XA_STATE(xas, &mapping->i_pages, start_pgoff);
struct folio *folio;
vm_fault_t ret = 0;
- int nr_pages = 0;
+ unsigned int nr_pages = 0, mmap_miss = 0, mmap_miss_saved;
rcu_read_lock();
folio = next_uptodate_folio(&xas, mapping, end_pgoff);
@@ -3569,25 +3594,27 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
end = folio->index + folio_nr_pages(folio) - 1;
nr_pages = min(end, end_pgoff) - xas.xa_index + 1;
- /*
- * NOTE: If there're PTE markers, we'll leave them to be
- * handled in the specific fault path, and it'll prohibit the
- * fault-around logic.
- */
- if (!pte_none(ptep_get(vmf->pte)))
- goto unlock;
-
- ret |= filemap_map_folio_range(vmf, folio,
- xas.xa_index - folio->index, addr, nr_pages);
+ if (!folio_test_large(folio))
+ ret |= filemap_map_order0_folio(vmf,
+ folio, addr, &mmap_miss);
+ else
+ ret |= filemap_map_folio_range(vmf, folio,
+ xas.xa_index - folio->index, addr,
+ nr_pages, &mmap_miss);
-unlock:
folio_unlock(folio);
folio_put(folio);
- folio = next_uptodate_folio(&xas, mapping, end_pgoff);
- } while (folio);
+ } while ((folio = next_uptodate_folio(&xas, mapping, end_pgoff)) != NULL);
pte_unmap_unlock(vmf->pte, vmf->ptl);
out:
rcu_read_unlock();
+
+ mmap_miss_saved = READ_ONCE(file->f_ra.mmap_miss);
+ if (mmap_miss >= mmap_miss_saved)
+ WRITE_ONCE(file->f_ra.mmap_miss, 0);
+ else
+ WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss_saved - mmap_miss);
+
return ret;
}
EXPORT_SYMBOL(filemap_map_pages);