Re: [PATCH v1 2/6] mm/hwpoison: remove race consideration
From: Ding Hui <hidden>
Date: 2021-06-15 12:57:16
Also in:
lkml
On 2021/6/14 10:12, Naoya Horiguchi wrote:
quoted hunk ↗ jump to hunk
@@ -1956,17 +1938,6 @@ int unpoison_memory(unsigned long pfn) goto unlock_mutex; } - /* - * unpoison_memory() can encounter thp only when the thp is being - * worked by memory_failure() and the page lock is not held yet. - * In such case, we yield to memory_failure() and make unpoison fail. - */ - if (!PageHuge(page) && PageTransHuge(page)) { - unpoison_pr_info("Unpoison: Memory failure is now running on %#lx\n", - pfn, &unpoison_rs); - goto unlock_mutex; - } -
if a huge page is in process of alloc or free, HUGETLB_PAGE_DTOR can be set after __SetPageHead() or be cleared before __ClearPageHead(), so this condition may be true in racy. Do we need the racy test for this situation?
if (!get_hwpoison_page(p, flags)) {
if (TestClearPageHWPoison(p))
num_poisoned_pages_dec();-- Thanks, - Ding Hui