Re: [PATCH] mm,hwpoison: Return -EBUSY when migration fails
From: Vlastimil Babka <hidden>
Date: 2020-12-09 10:26:30
On 12/9/20 10:28 AM, Oscar Salvador wrote:
Currently, we return -EIO when we fail to migrate the page. Migrations' failures are rather transient as they can happen due to several reasons, e.g: high page refcount bump, mapping->migrate_page failing etc. All meaning that at that time the page could not be migrated, but that has nothing to do with an EIO error. Let us return -EBUSY instead, as we do in case we failed to isolate the page. While are it, let us remove the "ret" print as its value does not change. Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Vlastimil Babka <redacted> Technically this affects madvise(2) so let's cc linux-api. The manpage doesn't document error codes of MADV_HWPOISON and MADV_SOFT_OFFLINE (besides EPERM) though so nothing to adjust there. It's meant only for the hwpoison testing suite anyway.
quoted hunk
--- mm/memory-failure.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 428991e297e2..1942fb83ac64 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c@@ -1849,11 +1849,11 @@ static int __soft_offline_page(struct page *page) pr_info("soft offline: %#lx: %s migration failed %d, type %lx (%pGp)\n", pfn, msg_page[huge], ret, page->flags, &page->flags); if (ret > 0) - ret = -EIO; + ret = -EBUSY; } } 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); + pr_info("soft offline: %#lx: %s isolation failed, page count %d, type %lx (%pGp)\n", + pfn, msg_page[huge], page_count(page), page->flags, &page->flags); ret = -EBUSY; } return ret;