* [PATCH 0/3] Cleanup and fixup for zswap
@ 2021-05-22 9:22 Miaohe Lin
2021-05-22 9:22 ` [PATCH 1/3] mm/zswap.c: remove unused function zswap_debugfs_exit() Miaohe Lin
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Miaohe Lin @ 2021-05-22 9:22 UTC (permalink / raw)
To: akpm, sjenning, ddstreet, vitaly.wool
Cc: bigeasy, nathan, colin.king, tiantao6, linux-kernel, linux-mm, linmiaohe
Hi all,
This series contains cleanups to remove unused function and avoid
unnecessary copy-in at map time. Also this fixes two bugs in the
function zswap_writeback_entry(). More details can be found in the
respective changelogs. Thanks!
Miaohe Lin (3):
mm/zswap.c: remove unused function zswap_debugfs_exit()
mm/zswap.c: avoid unnecessary copy-in at map time
mm/zswap.c: fix two bugs in zswap_writeback_entry()
mm/zswap.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)
--
2.23.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/3] mm/zswap.c: remove unused function zswap_debugfs_exit()
2021-05-22 9:22 [PATCH 0/3] Cleanup and fixup for zswap Miaohe Lin
@ 2021-05-22 9:22 ` Miaohe Lin
2021-05-22 9:22 ` [PATCH 2/3] mm/zswap.c: avoid unnecessary copy-in at map time Miaohe Lin
2021-05-22 9:22 ` [PATCH 3/3] mm/zswap.c: fix two bugs in zswap_writeback_entry() Miaohe Lin
2 siblings, 0 replies; 4+ messages in thread
From: Miaohe Lin @ 2021-05-22 9:22 UTC (permalink / raw)
To: akpm, sjenning, ddstreet, vitaly.wool
Cc: bigeasy, nathan, colin.king, tiantao6, linux-kernel, linux-mm, linmiaohe
zswap_debugfs_exit() is unused, remove it.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/zswap.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index 20763267a219..e93459319fdb 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1427,18 +1427,11 @@ static int __init zswap_debugfs_init(void)
return 0;
}
-
-static void __exit zswap_debugfs_exit(void)
-{
- debugfs_remove_recursive(zswap_debugfs_root);
-}
#else
static int __init zswap_debugfs_init(void)
{
return 0;
}
-
-static void __exit zswap_debugfs_exit(void) { }
#endif
/*********************************
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/3] mm/zswap.c: avoid unnecessary copy-in at map time
2021-05-22 9:22 [PATCH 0/3] Cleanup and fixup for zswap Miaohe Lin
2021-05-22 9:22 ` [PATCH 1/3] mm/zswap.c: remove unused function zswap_debugfs_exit() Miaohe Lin
@ 2021-05-22 9:22 ` Miaohe Lin
2021-05-22 9:22 ` [PATCH 3/3] mm/zswap.c: fix two bugs in zswap_writeback_entry() Miaohe Lin
2 siblings, 0 replies; 4+ messages in thread
From: Miaohe Lin @ 2021-05-22 9:22 UTC (permalink / raw)
To: akpm, sjenning, ddstreet, vitaly.wool
Cc: bigeasy, nathan, colin.king, tiantao6, linux-kernel, linux-mm, linmiaohe
The buf mapped via zpool_map_handle() is only used to store compressed
page buffer and there is no information to extract from it. So we could
use ZPOOL_MM_WO instead to avoid unnecessary copy-in at map time.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/zswap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index e93459319fdb..c27ce9f2cdf8 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1203,7 +1203,7 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
zswap_reject_alloc_fail++;
goto put_dstmem;
}
- buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_RW);
+ buf = zpool_map_handle(entry->pool->zpool, handle, ZPOOL_MM_WO);
memcpy(buf, &zhdr, hlen);
memcpy(buf + hlen, dst, dlen);
zpool_unmap_handle(entry->pool->zpool, handle);
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 3/3] mm/zswap.c: fix two bugs in zswap_writeback_entry()
2021-05-22 9:22 [PATCH 0/3] Cleanup and fixup for zswap Miaohe Lin
2021-05-22 9:22 ` [PATCH 1/3] mm/zswap.c: remove unused function zswap_debugfs_exit() Miaohe Lin
2021-05-22 9:22 ` [PATCH 2/3] mm/zswap.c: avoid unnecessary copy-in at map time Miaohe Lin
@ 2021-05-22 9:22 ` Miaohe Lin
2 siblings, 0 replies; 4+ messages in thread
From: Miaohe Lin @ 2021-05-22 9:22 UTC (permalink / raw)
To: akpm, sjenning, ddstreet, vitaly.wool
Cc: bigeasy, nathan, colin.king, tiantao6, linux-kernel, linux-mm, linmiaohe
In the ZSWAP_SWAPCACHE_FAIL and ZSWAP_SWAPCACHE_EXIST case, we forgot to
call zpool_unmap_handle() when zpool can't sleep. And we might sleep in
zswap_get_swap_cache_page() while zpool can't sleep. To fix all of these,
zpool_unmap_handle() should be done before zswap_get_swap_cache_page()
when zpool can't sleep.
Fixes: fc6697a89f56 ("mm/zswap: add the flag can_sleep_mapped")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/zswap.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/mm/zswap.c b/mm/zswap.c
index c27ce9f2cdf8..7944e3e57e78 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -967,6 +967,13 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
spin_unlock(&tree->lock);
BUG_ON(offset != entry->offset);
+ src = (u8 *)zhdr + sizeof(struct zswap_header);
+ if (!zpool_can_sleep_mapped(pool)) {
+ memcpy(tmp, src, entry->length);
+ src = tmp;
+ zpool_unmap_handle(pool, handle);
+ }
+
/* try to allocate swap cache page */
switch (zswap_get_swap_cache_page(swpentry, &page)) {
case ZSWAP_SWAPCACHE_FAIL: /* no memory or invalidate happened */
@@ -982,17 +989,7 @@ static int zswap_writeback_entry(struct zpool *pool, unsigned long handle)
case ZSWAP_SWAPCACHE_NEW: /* page is locked */
/* decompress */
acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx);
-
dlen = PAGE_SIZE;
- src = (u8 *)zhdr + sizeof(struct zswap_header);
-
- if (!zpool_can_sleep_mapped(pool)) {
-
- memcpy(tmp, src, entry->length);
- src = tmp;
-
- zpool_unmap_handle(pool, handle);
- }
mutex_lock(acomp_ctx->mutex);
sg_init_one(&input, src, entry->length);
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-05-22 9:23 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-22 9:22 [PATCH 0/3] Cleanup and fixup for zswap Miaohe Lin
2021-05-22 9:22 ` [PATCH 1/3] mm/zswap.c: remove unused function zswap_debugfs_exit() Miaohe Lin
2021-05-22 9:22 ` [PATCH 2/3] mm/zswap.c: avoid unnecessary copy-in at map time Miaohe Lin
2021-05-22 9:22 ` [PATCH 3/3] mm/zswap.c: fix two bugs in zswap_writeback_entry() Miaohe Lin
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