On Fri, Aug 14, 2020 at 7:24 AM Alexander Duyck <alexander.duyck@xxxxxxxxx> wrote: > > On Fri, Aug 14, 2020 at 12:19 AM Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> wrote: > > > > > > > > 在 2020/8/13 下午12:02, Alexander Duyck 写道: > > > > > > Since we have dropped the late abort case we can drop the code that was > > > clearing the LRU flag and calling page_put since the abort case will now > > > not be holding a reference to a page. > > > > > > Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx> > > > > seems the case-lru-file-mmap-read case drop about 3% on this patch in a rough testing. > > on my 80 core machine. > > I'm not sure how it could have that much impact on the performance > since the total effect would just be dropping what should be a > redundant test since we tested the skip bit before we took the LRU > bit, so we shouldn't need to test it again after. > > I finally got my test setup working last night. I'll have to do some > testing in my environment and I can start trying to see what is going > on. So I ran the case-lru-file-mmap-read a few times and I don't see how it is supposed to be testing the compaction code. It doesn't seem like compaction is running at least on my system as a result of the test script. I wonder if testing this code wouldn't be better done using something like thpscale from the mmtests(https://github.com/gormanm/mmtests)? It seems past changes to the compaction code were tested using that, and the config script for the test explains that it is designed specifically to stress the compaction code. I have the test up and running now and hope to collect results over the weekend. There is one change I will probably make to this patch and that is to place the new code that is setting skip_updated where the old code was calling test_and_set_skip_bit. By doing that we can avoid extra checks and it should help to reduce possible collisions when setting the skip bit in the pageblock flags. Thanks. - Alex
