Hello Sergey, On Sat, Jul 11, 2015 at 06:45:29PM +0900, Sergey Senozhatsky wrote: > Hello, > > First two patches introduce new zsmalloc zs_pages_to_compact() > symbol and change zram's `compact' sysfs attribute to be > read-write: > -- write triggers compaction, no changes > -- read returns the number of pages that compaction can > potentially free > > This lets user space to make a bit better decisions and to > avoid unneeded (which will not result in any significant > memory savings) compaction calls: > > Example: > > if [ `cat /sys/block/zram<id>/compact` -gt 10 ]; then > echo 1 > /sys/block/zram<id>/compact; > fi > > Up until now user space could not tell whether compaction > will result in any gain. First of all, thanks for the looking this. Question: What is motivation? IOW, did you see big overhead by user-triggered compaction? so, do you want to throttle it by userspace? > > The third patch removes class locking around zs_can_compact() > in zs_pages_to_compact(), the motivation and details are > provided in the commit message. > > Sergey Senozhatsky (3): > zsmalloc: factor out zs_pages_to_compact() > zram: make compact a read-write sysfs node > zsmalloc: do not take class lock in zs_pages_to_compact() > > Documentation/ABI/testing/sysfs-block-zram | 7 +++--- > Documentation/blockdev/zram.txt | 4 +++- > drivers/block/zram/zram_drv.c | 16 ++++++++++++- > include/linux/zsmalloc.h | 1 + > mm/zsmalloc.c | 37 +++++++++++++++++------------- > 5 files changed, 44 insertions(+), 21 deletions(-) > > -- > 2.4.5 > -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>