Messages in this thread | | | Date | Tue, 24 Jan 2023 10:38:35 -0800 | Subject | Re: [PATCH 8/9] mm/hugetlb: convert hugetlb_wp() to take in a folio | From | Sidhartha Kumar <> |
| |
On 1/24/23 7:23 AM, Gerald Schaefer wrote: > On Thu, 19 Jan 2023 13:14:45 -0800 > Sidhartha Kumar <sidhartha.kumar@oracle.com> wrote: > > [...] >> page = pte_page(entry); >> - if (page != pagecache_page) >> + if (page_folio(page) != pagecache_folio) >> if (!trylock_page(page)) { >> need_wait_lock = 1; >> goto out_ptl; >> } >> >> - get_page(page); >> + folio_get(pagecache_folio); >> > > We get a kernel crash on s390 in mprotect testcase from libhugetlbfs > testsuite, starting with next-20230120, bisected to this commit. > > We get here with pagecache_folio == NULL, and crash in folio_get(). > It doesn´t seem right to replace the get_page() with folio_get() > here, the matching put_page() at out_put_page: also wasn't changed > correspondingly. Also, pagecache_folio == NULL seems to be a valid > case here, on all architectures. > > Reverting this folio_get() to get_page() fixes the crash. Not sure > though if I missed something. I think you only want to replace > pagecache_page with pagecache_folio, like in the rest of the commit, > and not page -> pagecache_folio for this get_page(). Ya that get_page(page) line should have stayed how it was before as pagecache_folio is replacing instances of pagecache_page. Thanks for catching this, I'll fix this change in a v2 of this patch series.
Thanks, Sidhartha Kumar
| |