Den 2023-06-22 kl. 00:24, skrev Mike Kravetz: > This reverts commit 9425c591e06a9ab27a145ba655fb50532cf0bcc9 > > The reverted commit fixed up routines primarily used by readahead code > such that they could also be used by hugetlb. Unfortunately, this > caused a performance regression as pointed out by the Closes: tag. > > The hugetlb code which uses page_cache_next_miss will be addressed in > a subsequent patch. > > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > Closes: https://lore.kernel.org/oe-lkp/202306211346.1e9ff03e-oliver.sang@xxxxxxxxx > Fixes: 9425c591e06a ("page cache: fix page_cache_next/prev_miss off by one") > Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Should not this one be submitted to 6.4 stable branch too ? git describe --contains 9425c591e06a v6.4-rc7~29^2~1 The other one (hugetlb: revert use of page_cache_next_miss()) of this patch series landed in 6.4.2 Or am I missing something ? -- Thomas > --- > mm/filemap.c | 26 ++++++++++---------------- > 1 file changed, 10 insertions(+), 16 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 3b73101f9f86..9e44a49bbd74 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -1728,9 +1728,7 @@ bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm, > * > * Return: The index of the gap if found, otherwise an index outside the > * range specified (in which case 'return - index >= max_scan' will be true). > - * In the rare case of index wrap-around, 0 will be returned. 0 will also > - * be returned if index == 0 and there is a gap at the index. We can not > - * wrap-around if passed index == 0. > + * In the rare case of index wrap-around, 0 will be returned. > */ > pgoff_t page_cache_next_miss(struct address_space *mapping, > pgoff_t index, unsigned long max_scan) > @@ -1740,13 +1738,12 @@ pgoff_t page_cache_next_miss(struct address_space *mapping, > while (max_scan--) { > void *entry = xas_next(&xas); > if (!entry || xa_is_value(entry)) > - return xas.xa_index; > - if (xas.xa_index == 0 && index != 0) > - return xas.xa_index; > + break; > + if (xas.xa_index == 0) > + break; > } > > - /* No gaps in range and no wrap-around, return index beyond range */ > - return xas.xa_index + 1; > + return xas.xa_index; > } > EXPORT_SYMBOL(page_cache_next_miss); > > @@ -1767,9 +1764,7 @@ EXPORT_SYMBOL(page_cache_next_miss); > * > * Return: The index of the gap if found, otherwise an index outside the > * range specified (in which case 'index - return >= max_scan' will be true). > - * In the rare case of wrap-around, ULONG_MAX will be returned. ULONG_MAX > - * will also be returned if index == ULONG_MAX and there is a gap at the > - * index. We can not wrap-around if passed index == ULONG_MAX. > + * In the rare case of wrap-around, ULONG_MAX will be returned. > */ > pgoff_t page_cache_prev_miss(struct address_space *mapping, > pgoff_t index, unsigned long max_scan) > @@ -1779,13 +1774,12 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping, > while (max_scan--) { > void *entry = xas_prev(&xas); > if (!entry || xa_is_value(entry)) > - return xas.xa_index; > - if (xas.xa_index == ULONG_MAX && index != ULONG_MAX) > - return xas.xa_index; > + break; > + if (xas.xa_index == ULONG_MAX) > + break; > } > > - /* No gaps in range and no wrap-around, return index beyond range */ > - return xas.xa_index - 1; > + return xas.xa_index; > } > EXPORT_SYMBOL(page_cache_prev_miss); >
