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| author | Sergey Senozhatsky <senozhatsky@chromium.org> | 2024-03-29 12:39:41 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:30 +0300 |
| commit | 34efe1c3b688944d9817a5faaab7aad870182c59 (patch) | |
| tree | 4fe669a824efd2bd77bef4fd225a2abaa7baaba9 /drivers/block | |
| parent | ba42b524a0408b5f92bd41edaee1ea84309ab9ae (diff) | |
| download | linux-34efe1c3b688944d9817a5faaab7aad870182c59.tar.xz | |
zram: add max_pages param to recompression
Introduce "max_pages" param to recompress device attribute which sets an
upper limit on the number of entries (pages) zram attempts to recompress
(in this particular recompression call). S/W recompression can be quite
expensive so limiting the number of pages recompress touches can be quite
helpful.
Link: https://lkml.kernel.org/r/20240329094050.2815699-1-senozhatsky@chromium.org
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Acked-by: Brian Geffon <bgeffon@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index f0639df6cd18..4cf38f7d3e0a 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1568,7 +1568,8 @@ static int zram_bvec_write(struct zram *zram, struct bio_vec *bvec, * Corresponding ZRAM slot should be locked. */ static int zram_recompress(struct zram *zram, u32 index, struct page *page, - u32 threshold, u32 prio, u32 prio_max) + u64 *num_recomp_pages, u32 threshold, u32 prio, + u32 prio_max) { struct zcomp_strm *zstrm = NULL; unsigned long handle_old; @@ -1645,6 +1646,15 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page, if (!zstrm) return 0; + /* + * Decrement the limit (if set) on pages we can recompress, even + * when current recompression was unsuccessful or did not compress + * the page below the threshold, because we still spent resources + * on it. + */ + if (*num_recomp_pages) + *num_recomp_pages -= 1; + if (class_index_new >= class_index_old) { /* * Secondary algorithms failed to re-compress the page @@ -1710,6 +1720,7 @@ static ssize_t recompress_store(struct device *dev, struct zram *zram = dev_to_zram(dev); unsigned long nr_pages = zram->disksize >> PAGE_SHIFT; char *args, *param, *val, *algo = NULL; + u64 num_recomp_pages = ULLONG_MAX; u32 mode = 0, threshold = 0; unsigned long index; struct page *page; @@ -1732,6 +1743,17 @@ static ssize_t recompress_store(struct device *dev, continue; } + if (!strcmp(param, "max_pages")) { + /* + * Limit the number of entries (pages) we attempt to + * recompress. + */ + ret = kstrtoull(val, 10, &num_recomp_pages); + if (ret) + return ret; + continue; + } + if (!strcmp(param, "threshold")) { /* * We will re-compress only idle objects equal or @@ -1788,6 +1810,9 @@ static ssize_t recompress_store(struct device *dev, for (index = 0; index < nr_pages; index++) { int err = 0; + if (!num_recomp_pages) + break; + zram_slot_lock(zram, index); if (!zram_allocated(zram, index)) @@ -1807,8 +1832,8 @@ static ssize_t recompress_store(struct device *dev, zram_test_flag(zram, index, ZRAM_INCOMPRESSIBLE)) goto next; - err = zram_recompress(zram, index, page, threshold, - prio, prio_max); + err = zram_recompress(zram, index, page, &num_recomp_pages, + threshold, prio, prio_max); next: zram_slot_unlock(zram, index); if (err) { |