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| author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-05-12 20:23:02 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-05-13 07:20:15 -0700 |
| commit | e2e3fdc7d4afdb8e7ba981eba7827993f2d390a8 (patch) | |
| tree | f747a326065eb01d0e328a79751b06f464dd5292 /mm/swapfile.c | |
| parent | d33e4e1412c8b618f5f2f251ab9ddcfdf9f4adf3 (diff) | |
| download | lwn-e2e3fdc7d4afdb8e7ba981eba7827993f2d390a8.tar.gz lwn-e2e3fdc7d4afdb8e7ba981eba7827993f2d390a8.zip | |
swap: turn get_swap_page() into folio_alloc_swap()
This removes an assumption that a large folio is HPAGE_PMD_NR pages
in size.
Link: https://lkml.kernel.org/r/20220504182857.4013401-8-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/swapfile.c')
| -rw-r--r-- | mm/swapfile.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/mm/swapfile.c b/mm/swapfile.c index 9398e915b36b..bfa41bf5e190 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -77,9 +77,9 @@ static PLIST_HEAD(swap_active_head); /* * all available (active, not full) swap_info_structs * protected with swap_avail_lock, ordered by priority. - * This is used by get_swap_page() instead of swap_active_head + * This is used by folio_alloc_swap() instead of swap_active_head * because swap_active_head includes all swap_info_structs, - * but get_swap_page() doesn't need to look at full ones. + * but folio_alloc_swap() doesn't need to look at full ones. * This uses its own lock instead of swap_lock because when a * swap_info_struct changes between not-full/full, it needs to * add/remove itself to/from this list, but the swap_info_struct->lock @@ -2109,11 +2109,12 @@ retry: * Under global memory pressure, swap entries can be reinserted back * into process space after the mmlist loop above passes over them. * - * Limit the number of retries? No: when mmget_not_zero() above fails, - * that mm is likely to be freeing swap from exit_mmap(), which proceeds - * at its own independent pace; and even shmem_writepage() could have - * been preempted after get_swap_page(), temporarily hiding that swap. - * It's easy and robust (though cpu-intensive) just to keep retrying. + * Limit the number of retries? No: when mmget_not_zero() + * above fails, that mm is likely to be freeing swap from + * exit_mmap(), which proceeds at its own independent pace; + * and even shmem_writepage() could have been preempted after + * folio_alloc_swap(), temporarily hiding that swap. It's easy + * and robust (though cpu-intensive) just to keep retrying. */ if (READ_ONCE(si->inuse_pages)) { if (!signal_pending(current)) @@ -2327,7 +2328,7 @@ static void _enable_swap_info(struct swap_info_struct *p) * which on removal of any swap_info_struct with an auto-assigned * (i.e. negative) priority increments the auto-assigned priority * of any lower-priority swap_info_structs. - * swap_avail_head needs to be priority ordered for get_swap_page(), + * swap_avail_head needs to be priority ordered for folio_alloc_swap(), * which allocates swap pages from the highest available priority * swap_info_struct. */ |