diff options
| author |   Vitaly Wool <vitalywool@gmail.com> | 2019-05-13 17:22:46 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-14 09:47:50 -0700 |
| commit | 351618b203acef13946a03ecf18fbe328c3cdb58 (patch) | |
| tree | d50a6a22e0674d460c73acac7a03ab3d696bd9b6 /mm | |
| parent | mm/z3fold.c: introduce helper functions (diff) | |
| download | linux-dev-351618b203acef13946a03ecf18fbe328c3cdb58.tar.xz linux-dev-351618b203acef13946a03ecf18fbe328c3cdb58.zip | |
mm/z3fold.c: improve compression by extending search
The current z3fold implementation only searches this CPU's page lists for
a fitting page to put a new object into. This patch adds quick search for
very well fitting pages (i. e. those having exactly the required number
of free space) on other CPUs too, before allocating a new page for that
object.
Link: http://lkml.kernel.org/r/20190417103733.72ae81abe1552397c95a008e@gmail.com
Signed-off-by: Vitaly Wool <vitaly.vul@sony.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/z3fold.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/mm/z3fold.c b/mm/z3fold.c index 7a59875d880c..29a4f1249bef 100644 --- a/mm/z3fold.c +++ b/mm/z3fold.c @@ -522,6 +522,42 @@ lookup: } put_cpu_ptr(pool->unbuddied); + if (!zhdr) { + int cpu; + + /* look for _exact_ match on other cpus' lists */ + for_each_online_cpu(cpu) { + struct list_head *l; + + unbuddied = per_cpu_ptr(pool->unbuddied, cpu); + spin_lock(&pool->lock); + l = &unbuddied[chunks]; + + zhdr = list_first_entry_or_null(READ_ONCE(l), + struct z3fold_header, buddy); + + if (!zhdr || !z3fold_page_trylock(zhdr)) { + spin_unlock(&pool->lock); + zhdr = NULL; + continue; + } + list_del_init(&zhdr->buddy); + zhdr->cpu = -1; + spin_unlock(&pool->lock); + + page = virt_to_page(zhdr); + if (test_bit(NEEDS_COMPACTING, &page->private)) { + z3fold_page_unlock(zhdr); + zhdr = NULL; + if (can_sleep) + cond_resched(); + continue; + } + kref_get(&zhdr->refcount); + break; + } + } + return zhdr; } |