在 2020/9/22 下午1:27, Hugh Dickins 写道: > On Mon, 24 Aug 2020, Alex Shi wrote: > >> This patch moves per node lru_lock into lruvec, thus bring a lru_lock for >> each of memcg per node. So on a large machine, each of memcg don't >> have to suffer from per node pgdat->lru_lock competition. They could go >> fast with their self lru_lock. >> >> After move memcg charge before lru inserting, page isolation could >> serialize page's memcg, then per memcg lruvec lock is stable and could >> replace per node lru lock. >> >> In func isolate_migratepages_block, compact_unlock_should_abort is >> opend, and lock_page_lruvec logical is embedded for tight process. > > Hard to understand: perhaps: > > In func isolate_migratepages_block, compact_unlock_should_abort and > lock_page_lruvec_irqsave are open coded to work with compact_control. will update with your suggestion. Thanks! > >> Also add a debug func in locking which may give some clues if there are >> sth out of hands. >> >> According to Daniel Jordan's suggestion, I run 208 'dd' with on 104 >> containers on a 2s * 26cores * HT box with a modefied case: >> https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-lru-file-readtwice > > s/modeified/modified/ > lruv19 has an lkml.org link there, please substitut > https://lore.kernel.org/lkml/01ed6e45-3853-dcba-61cb-b429a49a7572@xxxxxxxxxxxxxxxxx/ > Thanks! >> >> With this and later patches, the readtwice performance increases >> about 80% within concurrent containers. >> >> On a large machine with memcg enabled but not used, the page's lruvec >> seeking pass a few pointers, that may lead to lru_lock holding time >> increase and a bit regression. >> >> Hugh Dickins helped on patch polish, thanks! >> >> Reported-by: kernel test robot <lkp@xxxxxxxxx> > > Eh? It may have reported some locking bugs somewhere, but this > is the main patch of your per-memcg lru_lock: I don't think the > kernel test robot inspired your whole design, did it? Delete that. > > >> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> > > I can't quite Ack this one yet, because there are several functions > (mainly __munlock_pagevec and check_move_unevictable_pages) which are > not right in this v18 version, and a bit tricky to correct: I already > suggested what to do in other mail, but this patch comes before > relock_page_lruvec, so must look different from the final result; > I need to look at a later version, perhaps already there in your > github tree, before I can Ack: but it's not far off. > Comments below. All suggestions are taken! Many thanks for so detailed review! A new branch with all comments is updated as https://github.com/alexshi/linux.git lruv19.5 A quick summary for the branch, Add a new patch for move_pages_to_lru: mm/vmscan: remove lruvec reget in move_pages_to_lru Add another patch for split part from 'Introduce TestClearPageLRU': mm/swap.c: reorder __ClearPageLRU and lruvec the mlock changes moved earlier: mm/mlock: remove __munlock_isolate_lru_page mm/mlock: remove __munlock_isolate_lru_page I am wondering if it's good to send out v19 here or maybe better to wait for your confirm if all suggestion/comments are settled? Thanks Alex
