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mm/truncate: batch-clear shadow entries

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Make clear_shadow_entry() clear shadow entries in `struct folio_batch` so
that it can reduce contention on i_lock and i_pages locks, e.g.,

  watchdog: BUG: soft lockup - CPU#29 stuck for 11s! [fio:2701649]
    clear_shadow_entry+0x3d/0x100
    mapping_try_invalidate+0x117/0x1d0
    invalidate_mapping_pages+0x10/0x20
    invalidate_bdev+0x3c/0x50
    blkdev_common_ioctl+0x5f7/0xa90
    blkdev_ioctl+0x109/0x270

Also, rename clear_shadow_entry() to clear_shadow_entries() accordingly.

[yuzhao@google.com: v2]
  Link: https://lkml.kernel.org/r/20240710060933.3979380-1-yuzhao@google.com
Link: https://lkml.kernel.org/r/20240708212753.3120511-1-yuzhao@google.com
Reported-by: Bharata B Rao <bharata@amd.com>
Closes: https://lore.kernel.org/d2841226-e27b-4d3d-a578-63587a3aa4f3@amd.com/
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yu Zhao 2024-07-08 15:27:53 -06:00 committed by Andrew Morton
parent 8a78882dac
commit 61c663e020
1 changed files with 31 additions and 37 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

68
mm/truncate.c
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@ -39,12 +39,25 @@ static inline void __clear_shadow_entry(struct address_space *mapping,
xas_store(&xas, NULL);
}
static void clear_shadow_entry(struct address_space *mapping, pgoff_t index,
void *entry)
static void clear_shadow_entries(struct address_space *mapping,
struct folio_batch *fbatch, pgoff_t *indices)
{
int i;
/* 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);
__clear_shadow_entry(mapping, index, entry);
for (i = 0; i < folio_batch_count(fbatch); i++) {
struct folio *folio = fbatch->folios[i];
if (xa_is_value(folio))
__clear_shadow_entry(mapping, indices[i], folio);
}
xa_unlock_irq(&mapping->i_pages);
if (mapping_shrinkable(mapping))
inode_add_lru(mapping->host);
@ -105,36 +118,6 @@ static void truncate_folio_batch_exceptionals(struct address_space *mapping,
fbatch->nr = j;
}
/*
* Invalidate exceptional entry if easily possible. This handles exceptional
* entries for invalidate_inode_pages().
*/
static int invalidate_exceptional_entry(struct address_space *mapping,
pgoff_t index, void *entry)
{
/* Handled by shmem itself, or for DAX we do nothing. */
if (shmem_mapping(mapping) || dax_mapping(mapping))
return 1;
clear_shadow_entry(mapping, index, entry);
return 1;
}
/*
* Invalidate exceptional entry if clean. This handles exceptional entries for
* invalidate_inode_pages2() so for DAX it evicts only clean entries.
*/
static int invalidate_exceptional_entry2(struct address_space *mapping,
pgoff_t index, void *entry)
{
/* Handled by shmem itself */
if (shmem_mapping(mapping))
return 1;
if (dax_mapping(mapping))
return dax_invalidate_mapping_entry_sync(mapping, index);
clear_shadow_entry(mapping, index, entry);
return 1;
}
/**
* folio_invalidate - Invalidate part or all of a folio.
* @folio: The folio which is affected.
@ -494,6 +477,7 @@ unsigned long mapping_try_invalidate(struct address_space *mapping,
unsigned long ret;
unsigned long count = 0;
int i;
bool xa_has_values = false;
folio_batch_init(&fbatch);
while (find_lock_entries(mapping, &index, end, &fbatch, indices)) {
@ -503,8 +487,8 @@ unsigned long mapping_try_invalidate(struct address_space *mapping,
/* We rely upon deletion not changing folio->index */
if (xa_is_value(folio)) {
count += invalidate_exceptional_entry(mapping,
indices[i], folio);
xa_has_values = true;
count++;
continue;
}
@ -522,6 +506,10 @@ unsigned long mapping_try_invalidate(struct address_space *mapping,
}
count += ret;
}
if (xa_has_values)
clear_shadow_entries(mapping, &fbatch, indices);
folio_batch_remove_exceptionals(&fbatch);
folio_batch_release(&fbatch);
cond_resched();
@ -616,6 +604,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
int ret = 0;
int ret2 = 0;
int did_range_unmap = 0;
bool xa_has_values = false;
if (mapping_empty(mapping))
return 0;
@ -629,8 +618,9 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
/* We rely upon deletion not changing folio->index */
if (xa_is_value(folio)) {
if (!invalidate_exceptional_entry2(mapping,
indices[i], folio))
xa_has_values = true;
if (dax_mapping(mapping) &&
!dax_invalidate_mapping_entry_sync(mapping, indices[i]))
ret = -EBUSY;
continue;
}
@ -666,6 +656,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
ret = ret2;
folio_unlock(folio);
}
if (xa_has_values)
clear_shadow_entries(mapping, &fbatch, indices);
folio_batch_remove_exceptionals(&fbatch);
folio_batch_release(&fbatch);
cond_resched();