diff options
| author | Minchan Kim <minchan@kernel.org> | 2014-04-08 00:38:21 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-08 01:36:02 +0200 |
| commit | 60a726e33375a1096e85399cfa1327081b4c38be (patch) | |
| tree | 3316be45cfc8844bdec5e742cac59f1ebc0dab2f /Documentation/blockdev | |
| parent | zram: return error-valued pointer from zcomp_create() (diff) | |
| download | linux-60a726e33375a1096e85399cfa1327081b4c38be.tar.xz linux-60a726e33375a1096e85399cfa1327081b4c38be.zip | |
zram: propagate error to user
When we initialized zcomp with single, we couldn't change
max_comp_streams without zram reset but current interface doesn't show
any error to user and even it changes max_comp_streams's value without
any effect so it would make user very confusing.
This patch prevents max_comp_streams's change when zcomp was initialized
as single zcomp and emit the error to user(ex, echo).
[akpm@linux-foundation.org: don't return with the lock held, per Sergey]
[fengguang.wu@intel.com: fix coccinelle warnings]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/blockdev')
| -rw-r--r-- | Documentation/blockdev/zram.txt | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 2604ffed51db..0595c3f56ccf 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -37,10 +37,11 @@ Note: In order to enable compression backend's multi stream support max_comp_streams must be initially set to desired concurrency level before ZRAM device initialisation. Once the device initialised as a single stream compression -backend (max_comp_streams equals to 0) changing the value of max_comp_streams -will not take any effect, because single stream compression backend implemented -as a special case and does not support dynamic max_comp_streams. Only multi -stream backend supports dynamic max_comp_streams adjustment. +backend (max_comp_streams equals to 1), you will see error if you try to change +the value of max_comp_streams because single stream compression backend +implemented as a special case by lock overhead issue and does not support +dynamic max_comp_streams. Only multi stream backend supports dynamic +max_comp_streams adjustment. 3) Select compression algorithm Using comp_algorithm device attribute one can see available and |