Re: [PATCH v3 0/5] HWpoison: further fixes and cleanups

[Oscar Salvador]

On Tue, Sep 15, 2020 at 05:22:22PM -0400, Aristeu Rozanski wrote:
> Hi Oscar, Naoya,

Hi Aristeu,

thanks for reporting this.

> I've run these tests using mmotm and mmotm with this patchset on top.

Could you please re-run the tests with the below patch applied, and
attached then the logs here?

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 84a7f228af36..d7b6e7724e47 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -67,6 +67,7 @@ atomic_long_t num_poisoned_pages __read_mostly = 
ATOMIC_LONG_INIT(0);
 
 static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, 
bool release)
 {
+       dump_page(page, "page_handle_poison");
        if (release) {
                put_page(page);
                drain_all_pages(page_zone(page));
@@ -77,7 +78,7 @@ static bool page_handle_poison(struct page *page, bool 
hugepage_or_freepage, boo
                 * Doing this check for free pages is also fine since 
dissolve_free_huge_page
                 * returns 0 for non-hugetlb pages as well.
                 */
-               if (dissolve_free_huge_page(page) || !take_page_off_buddy(page))
+               if (dissolve_free_huge_page(page) || 
!take_page_off_buddy(page)) {
                        /*
                         * We could fail to take off the target page from buddy
                         * for example due to racy page allocaiton, but that's
@@ -85,7 +86,9 @@ static bool page_handle_poison(struct page *page, bool 
hugepage_or_freepage, boo
                         * and if someone really want to use it, they should
                         * take it.
                         */
+                       pr_info("%s: hugepage_or_freepage failed¸n", __func__);
                        return false;
+               }
        }
 
        SetPageHWPoison(page);
@@ -1858,8 +1861,11 @@ static int __soft_offline_page(struct page *page)
                if (!ret) {
                        bool release = !huge;
 
-                       if (!page_handle_poison(page, true, release))
+                       if (!page_handle_poison(page, true, release)) {
+                               pr_info("%s: page_handle_poison -EBUSY\n", 
__func__);
+                               dump_page(page, "__soft_offline_page after 
migrate");
                                ret = -EBUSY;
+                       }
                } else {
                        if (!list_empty(&pagelist))
                                putback_movable_pages(&pagelist);
@@ -1872,6 +1878,7 @@ static int __soft_offline_page(struct page *page)
        } else {
                pr_info("soft offline: %#lx: %s isolation failed: %d, page 
count %d, type %lx (%pGp)\n",
                        pfn, msg_page[huge], ret, page_count(page), 
page->flags, &page->flags);
+               dump_page(page, "__soft_offline_page isolation failed");
                ret = -EBUSY;
        }
        return ret;
@@ -1882,8 +1889,11 @@ static int soft_offline_in_use_page(struct page *page)
        struct page *hpage = compound_head(page);
 
        if (!PageHuge(page) && PageTransHuge(hpage))
-               if (try_to_split_thp_page(page, "soft offline") < 0)
+               if (try_to_split_thp_page(page, "soft offline") < 0) {
+                       pr_info("%s: try_to_split_thp_page -EBUSY\n", __func__);
+                       dump_page(page, "try_to_split_thp_page");
                        return -EBUSY;
+               }
        return __soft_offline_page(page);
 }
 
@@ -1891,8 +1901,11 @@ static int soft_offline_free_page(struct page *page)
 {
        int rc = 0;
 
-       if (!page_handle_poison(page, true, false))
+       if (!page_handle_poison(page, true, false)) {
+               pr_info("%s: page_handle_poison -EBUSY\n", __func__);
+               dump_page(page, "soft_offline_free_page");
                rc = -EBUSY;
+       }
 
        return rc;
 }

Thanks

-- 
Oscar Salvador
SUSE L3