PDS Kernel Configuration

Merged upstream.

linux-tkg-patches/6.0/0012-misc-additions.patch

@@ -64,140 +64,6 @@ index 2c7171e0b0010..85de313ddec29 100644
  	select CPU_FREQ_GOV_PERFORMANCE
  	help
 
-From 2535fbde890f14c78b750139fcf87d1143850626 Mon Sep 17 00:00:00 2001
-From: Johannes Weiner <hannes@cmpxchg.org>
-Date: Tue, 2 Aug 2022 12:28:11 -0400
-Subject: [PATCH] mm: vmscan: fix extreme overreclaim and swap floods
-
-During proactive reclaim, we sometimes observe severe overreclaim, with
-several thousand times more pages reclaimed than requested.
-
-This trace was obtained from shrink_lruvec() during such an instance:
-
-    prio:0 anon_cost:1141521 file_cost:7767
-    nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
-    nr=[7161123 345 578 1111]
-
-While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
-by swapping.  These requests take over a minute, during which the write()
-to memory.reclaim is unkillably stuck inside the kernel.
-
-Digging into the source, this is caused by the proportional reclaim
-bailout logic.  This code tries to resolve a fundamental conflict: to
-reclaim roughly what was requested, while also aging all LRUs fairly and
-in accordance to their size, swappiness, refault rates etc.  The way it
-attempts fairness is that once the reclaim goal has been reached, it stops
-scanning the LRUs with the smaller remaining scan targets, and adjusts the
-remainder of the bigger LRUs according to how much of the smaller LRUs was
-scanned.  It then finishes scanning that remainder regardless of the
-reclaim goal.
-
-This works fine if priority levels are low and the LRU lists are
-comparable in size.  However, in this instance, the cgroup that is
-targeted by proactive reclaim has almost no files left - they've already
-been squeezed out by proactive reclaim earlier - and the remaining anon
-pages are hot.  Anon rotations cause the priority level to drop to 0,
-which results in reclaim targeting all of anon (a lot) and all of file
-(almost nothing).  By the time reclaim decides to bail, it has scanned
-most or all of the file target, and therefor must also scan most or all of
-the enormous anon target.  This target is thousands of times larger than
-the reclaim goal, thus causing the overreclaim.
-
-The bailout code hasn't changed in years, why is this failing now?  The
-most likely explanations are two other recent changes in anon reclaim:
-
-1. Before the series starting with commit 5df741963d52 ("mm: fix LRU
-   balancing effect of new transparent huge pages"), the VM was
-   overall relatively reluctant to swap at all, even if swap was
-   configured. This means the LRU balancing code didn't come into play
-   as often as it does now, and mostly in high pressure situations
-   where pronounced swap activity wouldn't be as surprising.
-
-2. For historic reasons, shrink_lruvec() loops on the scan targets of
-   all LRU lists except the active anon one, meaning it would bail if
-   the only remaining pages to scan were active anon - even if there
-   were a lot of them.
-
-   Before the series starting with commit ccc5dc67340c ("mm/vmscan:
-   make active/inactive ratio as 1:1 for anon lru"), most anon pages
-   would live on the active LRU; the inactive one would contain only a
-   handful of preselected reclaim candidates. After the series, anon
-   gets aged similarly to file, and the inactive list is the default
-   for new anon pages as well, making it often the much bigger list.
-
-   As a result, the VM is now more likely to actually finish large
-   anon targets than before.
-
-Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the
-larger LRU lists is made before bailing out on a met reclaim goal.
-
-This fixes the extreme overreclaim problem.
-
-Fairness is more subtle and harder to evaluate.  No obvious misbehavior
-was observed on the test workload, in any case.  Conceptually, fairness
-should primarily be a cumulative effect from regular, lower priority
-scans.  Once the VM is in trouble and needs to escalate scan targets to
-make forward progress, fairness needs to take a backseat.  This is also
-acknowledged by the myriad exceptions in get_scan_count().  This patch
-makes fairness decrease gradually, as it keeps fairness work static over
-increasing priority levels with growing scan targets.  This should make
-more sense - although we may have to re-visit the exact values.
-
-Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.org
-Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
-Reviewed-by: Rik van Riel <riel@surriel.com>
-Acked-by: Mel Gorman <mgorman@techsingularity.net>
-Cc: Hugh Dickins <hughd@google.com>
-Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
-Cc: <stable@vger.kernel.org>
-Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
----
- mm/vmscan.c | 10 ++++------
- 1 file changed, 4 insertions(+), 6 deletions(-)
-
-diff --git a/mm/vmscan.c b/mm/vmscan.c
-index 382dbe97329f33..266eb8cfe93a67 100644
---- a/mm/vmscan.c
-+++ b/mm/vmscan.c
-@@ -2955,8 +2955,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 	enum lru_list lru;
- 	unsigned long nr_reclaimed = 0;
- 	unsigned long nr_to_reclaim = sc->nr_to_reclaim;
-+	bool proportional_reclaim;
- 	struct blk_plug plug;
--	bool scan_adjusted;
-
- 	get_scan_count(lruvec, sc, nr);
-
-@@ -2974,8 +2974,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 	 * abort proportional reclaim if either the file or anon lru has already
- 	 * dropped to zero at the first pass.
- 	 */
--	scan_adjusted = (!cgroup_reclaim(sc) && !current_is_kswapd() &&
--			 sc->priority == DEF_PRIORITY);
-+	proportional_reclaim = (!cgroup_reclaim(sc) && !current_is_kswapd() &&
-+				sc->priority == DEF_PRIORITY);
-
- 	blk_start_plug(&plug);
- 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
-@@ -2995,7 +2995,7 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
-
- 		cond_resched();
-
--		if (nr_reclaimed < nr_to_reclaim || scan_adjusted)
-+		if (nr_reclaimed < nr_to_reclaim || proportional_reclaim)
- 			continue;
-
- 		/*
-@@ -3046,8 +3046,6 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 		nr_scanned = targets[lru] - nr[lru];
- 		nr[lru] = targets[lru] * (100 - percentage) / 100;
- 		nr[lru] -= min(nr[lru], nr_scanned);
--
--		scan_adjusted = true;
- 	}
- 	blk_finish_plug(&plug);
- 	sc->nr_reclaimed += nr_reclaimed;
 From 430daaab3c78de6bd82f10cfb5a0f016c6e583f6 Mon Sep 17 00:00:00 2001
 From: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
 Date: Mon, 4 Oct 2021 14:07:34 -0400

linux-tkg-patches/6.1/0012-misc-additions.patch

@@ -64,140 +64,6 @@ index 2c7171e0b0010..85de313ddec29 100644
  	select CPU_FREQ_GOV_PERFORMANCE
  	help
 
-From 2535fbde890f14c78b750139fcf87d1143850626 Mon Sep 17 00:00:00 2001
-From: Johannes Weiner <hannes@cmpxchg.org>
-Date: Tue, 2 Aug 2022 12:28:11 -0400
-Subject: [PATCH] mm: vmscan: fix extreme overreclaim and swap floods
-
-During proactive reclaim, we sometimes observe severe overreclaim, with
-several thousand times more pages reclaimed than requested.
-
-This trace was obtained from shrink_lruvec() during such an instance:
-
-    prio:0 anon_cost:1141521 file_cost:7767
-    nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190)
-    nr=[7161123 345 578 1111]
-
-While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it
-by swapping.  These requests take over a minute, during which the write()
-to memory.reclaim is unkillably stuck inside the kernel.
-
-Digging into the source, this is caused by the proportional reclaim
-bailout logic.  This code tries to resolve a fundamental conflict: to
-reclaim roughly what was requested, while also aging all LRUs fairly and
-in accordance to their size, swappiness, refault rates etc.  The way it
-attempts fairness is that once the reclaim goal has been reached, it stops
-scanning the LRUs with the smaller remaining scan targets, and adjusts the
-remainder of the bigger LRUs according to how much of the smaller LRUs was
-scanned.  It then finishes scanning that remainder regardless of the
-reclaim goal.
-
-This works fine if priority levels are low and the LRU lists are
-comparable in size.  However, in this instance, the cgroup that is
-targeted by proactive reclaim has almost no files left - they've already
-been squeezed out by proactive reclaim earlier - and the remaining anon
-pages are hot.  Anon rotations cause the priority level to drop to 0,
-which results in reclaim targeting all of anon (a lot) and all of file
-(almost nothing).  By the time reclaim decides to bail, it has scanned
-most or all of the file target, and therefor must also scan most or all of
-the enormous anon target.  This target is thousands of times larger than
-the reclaim goal, thus causing the overreclaim.
-
-The bailout code hasn't changed in years, why is this failing now?  The
-most likely explanations are two other recent changes in anon reclaim:
-
-1. Before the series starting with commit 5df741963d52 ("mm: fix LRU
-   balancing effect of new transparent huge pages"), the VM was
-   overall relatively reluctant to swap at all, even if swap was
-   configured. This means the LRU balancing code didn't come into play
-   as often as it does now, and mostly in high pressure situations
-   where pronounced swap activity wouldn't be as surprising.
-
-2. For historic reasons, shrink_lruvec() loops on the scan targets of
-   all LRU lists except the active anon one, meaning it would bail if
-   the only remaining pages to scan were active anon - even if there
-   were a lot of them.
-
-   Before the series starting with commit ccc5dc67340c ("mm/vmscan:
-   make active/inactive ratio as 1:1 for anon lru"), most anon pages
-   would live on the active LRU; the inactive one would contain only a
-   handful of preselected reclaim candidates. After the series, anon
-   gets aged similarly to file, and the inactive list is the default
-   for new anon pages as well, making it often the much bigger list.
-
-   As a result, the VM is now more likely to actually finish large
-   anon targets than before.
-
-Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the
-larger LRU lists is made before bailing out on a met reclaim goal.
-
-This fixes the extreme overreclaim problem.
-
-Fairness is more subtle and harder to evaluate.  No obvious misbehavior
-was observed on the test workload, in any case.  Conceptually, fairness
-should primarily be a cumulative effect from regular, lower priority
-scans.  Once the VM is in trouble and needs to escalate scan targets to
-make forward progress, fairness needs to take a backseat.  This is also
-acknowledged by the myriad exceptions in get_scan_count().  This patch
-makes fairness decrease gradually, as it keeps fairness work static over
-increasing priority levels with growing scan targets.  This should make
-more sense - although we may have to re-visit the exact values.
-
-Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.org
-Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
-Reviewed-by: Rik van Riel <riel@surriel.com>
-Acked-by: Mel Gorman <mgorman@techsingularity.net>
-Cc: Hugh Dickins <hughd@google.com>
-Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
-Cc: <stable@vger.kernel.org>
-Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
----
- mm/vmscan.c | 10 ++++------
- 1 file changed, 4 insertions(+), 6 deletions(-)
-
-diff --git a/mm/vmscan.c b/mm/vmscan.c
-index 382dbe97329f33..266eb8cfe93a67 100644
---- a/mm/vmscan.c
-+++ b/mm/vmscan.c
-@@ -2955,8 +2955,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 	enum lru_list lru;
- 	unsigned long nr_reclaimed = 0;
- 	unsigned long nr_to_reclaim = sc->nr_to_reclaim;
-+	bool proportional_reclaim;
- 	struct blk_plug plug;
--	bool scan_adjusted;
-
- 	get_scan_count(lruvec, sc, nr);
-
-@@ -2974,8 +2974,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 	 * abort proportional reclaim if either the file or anon lru has already
- 	 * dropped to zero at the first pass.
- 	 */
--	scan_adjusted = (!cgroup_reclaim(sc) && !current_is_kswapd() &&
--			 sc->priority == DEF_PRIORITY);
-+	proportional_reclaim = (!cgroup_reclaim(sc) && !current_is_kswapd() &&
-+				sc->priority == DEF_PRIORITY);
-
- 	blk_start_plug(&plug);
- 	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
-@@ -2995,7 +2995,7 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
-
- 		cond_resched();
-
--		if (nr_reclaimed < nr_to_reclaim || scan_adjusted)
-+		if (nr_reclaimed < nr_to_reclaim || proportional_reclaim)
- 			continue;
-
- 		/*
-@@ -3046,8 +3046,6 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
- 		nr_scanned = targets[lru] - nr[lru];
- 		nr[lru] = targets[lru] * (100 - percentage) / 100;
- 		nr[lru] -= min(nr[lru], nr_scanned);
--
--		scan_adjusted = true;
- 	}
- 	blk_finish_plug(&plug);
- 	sc->nr_reclaimed += nr_reclaimed;
 From 430daaab3c78de6bd82f10cfb5a0f016c6e583f6 Mon Sep 17 00:00:00 2001
 From: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>
 Date: Mon, 4 Oct 2021 14:07:34 -0400