6.1-stable patches

added patches:
	revert-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch

diff --git a/queue-6.1/revert-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch b/queue-6.1/revert-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch
new file mode 100644 (file)
index 0000000..dfa2478
--- /dev/null
+++ b/queue-6.1/revert-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch
@@ -0,0 +1,61 @@
+From 95e7a450b8190673675836bfef236262ceff084a Mon Sep 17 00:00:00 2001
+From: Vlastimil Babka <vbabka@suse.cz>
+Date: Fri, 13 Jan 2023 18:33:45 +0100
+Subject: Revert "mm/compaction: fix set skip in fast_find_migrateblock"
+
+From: Vlastimil Babka <vbabka@suse.cz>
+
+commit 95e7a450b8190673675836bfef236262ceff084a upstream.
+
+This reverts commit 7efc3b7261030da79001c00d92bc3392fd6c664c.
+
+We have got openSUSE reports (Link 1) for 6.1 kernel with khugepaged
+stalling CPU for long periods of time.  Investigation of tracepoint data
+shows that compaction is stuck in repeating fast_find_migrateblock()
+based migrate page isolation, and then fails to migrate all isolated
+pages.
+
+Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
+was suspected as it was merged in 6.1 and in theory can indeed remove a
+termination condition for fast_find_migrateblock() under certain
+conditions, as it removes a place that always marks a scanned pageblock
+from being re-scanned.  There are other such places, but those can be
+skipped under certain conditions, which seems to match the tracepoint
+data.
+
+Testing of revert also appears to have resolved the issue, thus revert
+the commit until a more robust solution for the original problem is
+developed.
+
+It's also likely this will fix qemu stalls with 6.1 kernel reported in
+Link 2, but that is not yet confirmed.
+
+Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848
+Link: https://lore.kernel.org/kvm/b8017e09-f336-3035-8344-c549086c2340@kernel.org/
+Link: https://lore.kernel.org/lkml/20230125134434.18017-1-mgorman@techsingularity.net/
+Fixes: 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock")
+Cc: <stable@vger.kernel.org>
+Tested-by: Pedro Falcato <pedro.falcato@gmail.com>
+Acked-by: Mel Gorman <mgorman@techsingularity.net>
+Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/compaction.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/mm/compaction.c b/mm/compaction.c
+index ca1603524bbe..8238e83385a7 100644
+--- a/mm/compaction.c
++++ b/mm/compaction.c
+@@ -1839,6 +1839,7 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc)
+                                       pfn = cc->zone->zone_start_pfn;
+                               cc->fast_search_fail = 0;
+                               found_block = true;
++                              set_pageblock_skip(freepage);
+                               break;
+                       }
+               }
+-- 
+2.39.1
+

diff --git a/queue-6.1/series b/queue-6.1/series
index 99eb6c98fc3d43f9eaf2e93b6bed6d980e103ab7..28d7aa142272a52dd618d599173247a5c07d70ea 100644 (file)
--- a/queue-6.1/series
+++ b/queue-6.1/series
@@ -300,3 +300,4 @@ block-ublk-move-ublk_chr_class-destroying-after-devi.patch
 treewide-fix-up-files-incorrectly-marked-executable.patch
 tools-gpio-fix-c-option-of-gpio-event-mon.patch
 fix-up-more-non-executable-files-marked-executable.patch
+revert-mm-compaction-fix-set-skip-in-fast_find_migrateblock.patch