On 01/15/2014 02:11 AM, Minchan Kim wrote: > 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(-) >
The new locking scheme seems sound to me. Acked-by: Jerome Marchand <[email protected]> -- 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/
