The patch titled
Subject: mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUND
has been added to the -mm mm-unstable branch. Its filename is
mm-memory-failure-remove-obsolete-mf_msg_different_compound.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-failure-remove-obsolete-mf_msg_different_compound.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUND
Date: Mon, 8 Jul 2024 11:05:44 +0800
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 So the MF_MSG_DIFFERENT_COMPOUND case is
obsolete and can be removed to get rid of this false assumption and code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@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Naoya Horiguchi <nao.horiguchi@xxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/ras/ras_event.h | 1 -
mm/memory-failure.c | 19 +++----------------
2 files changed, 3 insertions(+), 17 deletions(-)
--- a/include/ras/ras_event.h~mm-memory-failure-remove-obsolete-mf_msg_different_compound
+++ a/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" ) \
--- a/mm/memory-failure.c~mm-memory-failure-remove-obsolete-mf_msg_different_compound
+++ a/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 @@ try_again:
/*
* 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
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-memory-failure-remove-obsolete-mf_msg_different_compound.patch
