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mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUND

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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  So the MF_MSG_DIFFERENT_COMPOUND case is
obsolete and can be removed to get rid of this false assumption and code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 <linmiaohe@huawei.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Miaohe Lin 2024-07-08 11:05:44 +08:00 committed by Andrew Morton
parent a5ea521250
commit 8a78882dac
2 changed files with 3 additions and 17 deletions
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1
include/ras/ras_event.h
View File

@ -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" ) \

19
mm/memory-failure.c
View File

@ -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