On 1/4/21 7:46 PM, Muchun Song wrote: > On Tue, Jan 5, 2021 at 11:14 AM Muchun Song <songmuchun@xxxxxxxxxxxxx> wrote: >> >> On Tue, Jan 5, 2021 at 9:33 AM Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: >>> >>> On 1/3/21 10:58 PM, Muchun Song wrote: >>>> When dissolve_free_huge_page() races with __free_huge_page(), we can >>>> do a retry. Because the race window is small. >>> >>> In general, I agree that the race window is small. However, worst case >>> would be if the freeing of the page is put on a work queue. Is it acceptable >>> to keep retrying in that case? In addition, the 'Free some vmemmap' series >>> may slow the free_huge_page path even more. >> >> I also consider the 'Free some vmemmap' series case. In my next >> version series, I will flush the work before dissolve_free_huge_page >> returns when encountering this race. So the retry is acceptable. >> Right? > > Hi Mike, > > How about flushing the @free_hpage_work when > encountering this race? Flushing should be fine. The more I think about it, the more I think spinning to retry is not going to be an issue. Why? As you mentioned the race window is quite small. It just makes me a bit nervous to retry in a tight loop. -- Mike Kravetz
