On Mon, Jun 25, 2018 at 4:08 AM Li Wang <wangli.ahau@xxxxxxxxx> wrote: > > On 30 May 2018 at 20:53, Dan Streetman <ddstreet@xxxxxxxx> wrote: > > On Wed, May 30, 2018 at 6:39 AM, Li Wang <liwang@xxxxxxxxxx> wrote: > >> The '/sys/../zswap/stored_pages:' keep raising in zswap test with > >> "zswap.max_pool_percent=0" parameter. But theoretically, it should > >> not compress or store pages any more since there is no space in > >> compressed pool. > >> > >> Reproduce steps: > >> 1. Boot kernel with "zswap.enabled=1" > >> 2. Set the max_pool_percent to 0 > >> # echo 0 > /sys/module/zswap/parameters/max_pool_percent > >> 3. Do memory stress test to see if some pages have been compressed > >> # stress --vm 1 --vm-bytes $mem_available"M" --timeout 60s > >> 4. Watching the 'stored_pages' number increasing or not > >> > >> The root cause is: > >> When zswap_max_pool_percent is setting to 0 via kernel parameter, the > >> zswap_is_full() will always return true to do zswap_shrink(). But if > >> the shinking is able to reclain a page successful, then proceeds to > >> compress/store another page, so the value of stored_pages will keep > >> changing. > >> > >> To solve the issue, this patch adds zswap_is_full() check again after > >> zswap_shrink() to make sure it's now under the max_pool_percent, and > >> not to compress/store if reach its limitaion. > >> > >> Signed-off-by: Li Wang <liwang@xxxxxxxxxx> > > > > Acked-by: Dan Streetman <ddstreet@xxxxxxxx> > > ping~ > > Any possible to merge this in kernel-4.18-rcX? My zswap test always > fails on the upstream kernel. cc'ing Andrew as he may have missed this. > > > -- > Regards, > Li Wang > Email: wangli.ahau@xxxxxxxxx
