Currently, zram->lock rw_semaphore is coarse-grained so it hurts for scalability. This patch try to enhance it with remove the lock in read path.
[1] uses atomic opeartion so it removes dependency of 32bit stat from zram->lock. [2] introduces table own lock instead of relying on zram->lock. [3] remove free pending slot mess so it makes core very clean. [4] finally removes zram->lock in read path and changes it with mutex. So, output is wonderful. read/write mixed workload performs well 11 times than old and write concurrency is also enhanced because mutex supports SPIN_ON_OWNER while rw_semaphore doesn't yet. (I know recenty there were some effort to enhance it for rw_semaphore from Tim Chen but not sure it got merged. Anyway, we don't need it any more and there is no reason to prevent read-write concurrency) Thanks. Minchan Kim (4): [1] zram: use atomic operation for stat [2] zram: introduce zram->tb_lock [3] zram: remove workqueue for freeing removed pending slot [4] zram: Remove zram->lock in read path and change it with mutex drivers/staging/zram/zram_drv.c | 117 ++++++++++++++++------------------------ drivers/staging/zram/zram_drv.h | 27 +++------- 2 files changed, 51 insertions(+), 93 deletions(-) -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
