mm/memory-failure.c: simplify num_poisoned_pages_dec

Don't decrease the number of poisoned pages in page_alloc.c, let the
memory-failure.c do inc/dec poisoned pages only.

Also simplify unpoison_memory(), only decrease the number of
poisoned pages when:
 - TestClearPageHWPoison() succeed
 - put_page_back_buddy succeed

After decreasing, print necessary log.

Finally, remove clear_page_hwpoison() and unpoison_taken_off_page().

Link: https://lkml.kernel.org/r/20220509105641.491313-3-pizhenwei@bytedance.com
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e7a13e90bd05059ca03247258a12eacc790adc31..837975af2152c0c4d8330e316613a290d8539aa3 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2092,28 +2092,6 @@ core_initcall(memory_failure_init);
                pr_info(fmt, pfn);                      \
 })
 
-static inline int clear_page_hwpoison(struct ratelimit_state *rs, struct page *p)
-{
-       if (TestClearPageHWPoison(p)) {
-               unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
-                                page_to_pfn(p), rs);
-               num_poisoned_pages_dec();
-               return 1;
-       }
-       return 0;
-}
-
-static inline int unpoison_taken_off_page(struct ratelimit_state *rs,
-                                         struct page *p)
-{
-       if (put_page_back_buddy(p)) {
-               unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
-                                page_to_pfn(p), rs);
-               return 0;
-       }
-       return -EBUSY;
-}
-
 /**
  * unpoison_memory - Unpoison a previously poisoned page
  * @pfn: Page number of the to be unpoisoned page
@@ -2131,6 +2109,7 @@ int unpoison_memory(unsigned long pfn)
        struct page *page;
        struct page *p;
        int ret = -EBUSY;
+       int freeit = 0;
        static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL,
                                        DEFAULT_RATELIMIT_BURST);
 
@@ -2171,18 +2150,15 @@ int unpoison_memory(unsigned long pfn)
 
        ret = get_hwpoison_page(p, MF_UNPOISON);
        if (!ret) {
-               if (clear_page_hwpoison(&unpoison_rs, page))
-                       ret = 0;
-               else
-                       ret = -EBUSY;
+               ret = TestClearPageHWPoison(page) ? 0 : -EBUSY;
        } else if (ret < 0) {
                if (ret == -EHWPOISON) {
-                       ret = unpoison_taken_off_page(&unpoison_rs, p);
+                       ret = put_page_back_buddy(p) ? 0 : -EBUSY;
                } else
                        unpoison_pr_info("Unpoison: failed to grab page %#lx\n",
                                         pfn, &unpoison_rs);
        } else {
-               int freeit = clear_page_hwpoison(&unpoison_rs, p);
+               freeit = !!TestClearPageHWPoison(p);
 
                put_page(page);
                if (freeit && !(pfn == my_zero_pfn(0) && page_count(p) == 1)) {
@@ -2193,6 +2169,11 @@ int unpoison_memory(unsigned long pfn)
 
 unlock_mutex:
        mutex_unlock(&mf_mutex);
+       if (!ret || freeit) {
+               num_poisoned_pages_dec();
+               unpoison_pr_info("Unpoison: Software-unpoisoned page %#lx\n",
+                                page_to_pfn(p), &unpoison_rs);
+       }
        return ret;
 }
 EXPORT_SYMBOL(unpoison_memory);

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 732e01e9d0e0cdd0b0ccc9fc431699b2168d068c..a4a8fbbd6217fe603de2cd2177cacd3fef608c3d 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -9497,7 +9497,6 @@ bool put_page_back_buddy(struct page *page)
                ClearPageHWPoisonTakenOff(page);
                __free_one_page(page, pfn, zone, 0, migratetype, FPI_NONE);
                if (TestClearPageHWPoison(page)) {
-                       num_poisoned_pages_dec();
                        ret = true;
                }
        }