Hi Nhat, I want want to share the high level feedback we discussed here in the mailing list as well. It is my observation that each memcg LRU list can't compare the page time order with other memcg. It works great when the leaf level memcg hits the memory limit and you want to reclaim from that memcg. It works less well on the global memory pressure you need to reclaim from all memcg. You kind of have to scan each all child memcg to find out the best page to shrink from. It is less effective to get to the most desirable page quickly. This can benefit from a design similar to MGLRU. This idea is suggested by Yu Zhao, credit goes to him not me. In other words, the current patch is similar to the memcg page list pre MGLRU world. We can have a MRLRU like per memcg zswap shrink list. Chris On Wed, Nov 8, 2023 at 6:10 PM Chris Li <chrisl@xxxxxxxxxx> wrote: > > On Wed, Nov 8, 2023 at 4:28 PM Nhat Pham <nphamcs@xxxxxxxxx> wrote: > > > > Hmm my guess is that I probably sent this out based on an outdated > > mm-unstable. There has since been a new zswap selftest merged > > to mm-unstable (written by no other than myself - oh the irony), so > > maybe it does not apply cleanly anymore with git am. > > $ git am -3 patches/zswap-pool-lru/0005 > Applying: selftests: cgroup: update per-memcg zswap writeback selftest > Using index info to reconstruct a base tree... > M tools/testing/selftests/cgroup/test_zswap.c > Falling back to patching base and 3-way merge... > Auto-merging tools/testing/selftests/cgroup/test_zswap.c > $ git am -3 patches/zswap-pool-lru/0006 > Applying: zswap: shrinks zswap pool based on memory pressure > error: sha1 information is lacking or useless (mm/zswap.c). > error: could not build fake ancestor > Patch failed at 0001 zswap: shrinks zswap pool based on memory pressure > hint: Use 'git am --show-current-patch=diff' to see the failed patch > When you have resolved this problem, run "git am --continue". > If you prefer to skip this patch, run "git am --skip" instead. > To restore the original branch and stop patching, run "git am --abort". > > I was able to resolve the conflict on patch 6 by hand though. So I am good now. > > Thanks > > Chris
