From 8a78882dac1c8c464e047a29415edb50421651ce Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Mon, 8 Jul 2024 11:05:44 +0800 Subject: [PATCH] mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUND The page cannot become compound pages again just after a folio is split as an extra refcnt is held. So the MF_MSG_DIFFERENT_COMPOUND case is obsolete and can be removed to get rid of this false assumption and code burden. But add one WARN_ON() here to keep the situation clear. Link: https://lkml.kernel.org/r/20240708030544.196919-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Cc: Borislav Petkov (AMD) Cc: Naoya Horiguchi Cc: Tony Luck Signed-off-by: Andrew Morton --- include/ras/ras_event.h | 1 - mm/memory-failure.c | 19 +++---------------- 2 files changed, 3 insertions(+), 17 deletions(-) diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h index 9bc707fe88190..e5f7ee0864e78 100644 --- a/include/ras/ras_event.h +++ b/include/ras/ras_event.h @@ -356,7 +356,6 @@ TRACE_EVENT(aer_event, #define MF_PAGE_TYPE \ EM ( MF_MSG_KERNEL, "reserved kernel page" ) \ EM ( MF_MSG_KERNEL_HIGH_ORDER, "high-order kernel page" ) \ - EM ( MF_MSG_DIFFERENT_COMPOUND, "different compound page after locking" ) \ EM ( MF_MSG_HUGE, "huge page" ) \ EM ( MF_MSG_FREE_HUGE, "free huge page" ) \ EM ( MF_MSG_GET_HWPOISON, "get hwpoison page" ) \ diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 16f8651436d5e..581d3e5c91175 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -919,7 +919,6 @@ static const char *action_name[] = { static const char * const action_page_types[] = { [MF_MSG_KERNEL] = "reserved kernel page", [MF_MSG_KERNEL_HIGH_ORDER] = "high-order kernel page", - [MF_MSG_DIFFERENT_COMPOUND] = "different compound page after locking", [MF_MSG_HUGE] = "huge page", [MF_MSG_FREE_HUGE] = "free huge page", [MF_MSG_GET_HWPOISON] = "get hwpoison page", @@ -2349,22 +2348,10 @@ int memory_failure(unsigned long pfn, int flags) /* * We're only intended to deal with the non-Compound page here. - * However, the page could have changed compound pages due to - * race window. If this happens, we could try again to hopefully - * handle the page next round. + * The page cannot become compound pages again as folio has been + * splited and extra refcnt is held. */ - if (folio_test_large(folio)) { - if (retry) { - ClearPageHWPoison(p); - folio_unlock(folio); - folio_put(folio); - flags &= ~MF_COUNT_INCREASED; - retry = false; - goto try_again; - } - res = action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); - goto unlock_page; - } + WARN_ON(folio_test_large(folio)); /* * We use page flags to determine what action should be taken, but