Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
- drivers/net/can/flexcan.c | 1 +
+ drivers/net/can/flexcan.c | 1 +
1 file changed, 1 insertion(+)
-diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
-index baef09b9449f9..6b866d0451b21 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
-@@ -923,6 +923,7 @@ static int flexcan_chip_start(struct net_device *dev)
+@@ -923,6 +923,7 @@ static int flexcan_chip_start(struct net
reg_mecr = flexcan_read(®s->mecr);
reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
flexcan_write(reg_mecr, ®s->mecr);
reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
FLEXCAN_MECR_FANCEI_MSK);
flexcan_write(reg_mecr, ®s->mecr);
---
-2.20.1
-
--- /dev/null
+From 65de03e251382306a4575b1779c57c87889eee49 Mon Sep 17 00:00:00 2001
+From: Tejun Heo <tj@kernel.org>
+Date: Fri, 8 Nov 2019 12:18:29 -0800
+Subject: cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead
+
+From: Tejun Heo <tj@kernel.org>
+
+commit 65de03e251382306a4575b1779c57c87889eee49 upstream.
+
+cgroup writeback tries to refresh the associated wb immediately if the
+current wb is dead. This is to avoid keeping issuing IOs on the stale
+wb after memcg - blkcg association has changed (ie. when blkcg got
+disabled / enabled higher up in the hierarchy).
+
+Unfortunately, the logic gets triggered spuriously on inodes which are
+associated with dead cgroups. When the logic is triggered on dead
+cgroups, the attempt fails only after doing quite a bit of work
+allocating and initializing a new wb.
+
+While c3aab9a0bd91 ("mm/filemap.c: don't initiate writeback if mapping
+has no dirty pages") alleviated the issue significantly as it now only
+triggers when the inode has dirty pages. However, the condition can
+still be triggered before the inode is switched to a different cgroup
+and the logic simply doesn't make sense.
+
+Skip the immediate switching if the associated memcg is dying.
+
+This is a simplified version of the following two patches:
+
+ * https://lore.kernel.org/linux-mm/20190513183053.GA73423@dennisz-mbp/
+ * http://lkml.kernel.org/r/156355839560.2063.5265687291430814589.stgit@buzz
+
+Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
+Fixes: e8a7abf5a5bd ("writeback: disassociate inodes from dying bdi_writebacks")
+Acked-by: Dennis Zhou <dennis@kernel.org>
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Signed-off-by: Jens Axboe <axboe@kernel.dk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/fs-writeback.c | 9 ++++++---
+ 1 file changed, 6 insertions(+), 3 deletions(-)
+
+--- a/fs/fs-writeback.c
++++ b/fs/fs-writeback.c
+@@ -582,10 +582,13 @@ void wbc_attach_and_unlock_inode(struct
+ spin_unlock(&inode->i_lock);
+
+ /*
+- * A dying wb indicates that the memcg-blkcg mapping has changed
+- * and a new wb is already serving the memcg. Switch immediately.
++ * A dying wb indicates that either the blkcg associated with the
++ * memcg changed or the associated memcg is dying. In the first
++ * case, a replacement wb should already be available and we should
++ * refresh the wb immediately. In the second case, trying to
++ * refresh will keep failing.
+ */
+- if (unlikely(wb_dying(wbc->wb)))
++ if (unlikely(wb_dying(wbc->wb) && !css_is_dying(wbc->wb->memcg_css)))
+ inode_switch_wbs(inode, wbc->wb_id);
+ }
+
--- /dev/null
+From c3aab9a0bd91b696a852169479b7db1ece6cbf8c Mon Sep 17 00:00:00 2001
+From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
+Date: Mon, 23 Sep 2019 15:34:45 -0700
+Subject: mm/filemap.c: don't initiate writeback if mapping has no dirty pages
+
+From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
+
+commit c3aab9a0bd91b696a852169479b7db1ece6cbf8c upstream.
+
+Functions like filemap_write_and_wait_range() should do nothing if inode
+has no dirty pages or pages currently under writeback. But they anyway
+construct struct writeback_control and this does some atomic operations if
+CONFIG_CGROUP_WRITEBACK=y - on fast path it locks inode->i_lock and
+updates state of writeback ownership, on slow path might be more work.
+Current this path is safely avoided only when inode mapping has no pages.
+
+For example generic_file_read_iter() calls filemap_write_and_wait_range()
+at each O_DIRECT read - pretty hot path.
+
+This patch skips starting new writeback if mapping has no dirty tags set.
+If writeback is already in progress filemap_write_and_wait_range() will
+wait for it.
+
+Link: http://lkml.kernel.org/r/156378816804.1087.8607636317907921438.stgit@buzz
+Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
+Reviewed-by: Jan Kara <jack@suse.cz>
+Cc: Tejun Heo <tj@kernel.org>
+Cc: Jens Axboe <axboe@kernel.dk>
+Cc: Johannes Weiner <hannes@cmpxchg.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/filemap.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/mm/filemap.c
++++ b/mm/filemap.c
+@@ -340,7 +340,8 @@ int __filemap_fdatawrite_range(struct ad
+ .range_end = end,
+ };
+
+- if (!mapping_cap_writeback_dirty(mapping))
++ if (!mapping_cap_writeback_dirty(mapping) ||
++ !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
+ return 0;
+
+ wbc_attach_fdatawrite_inode(&wbc, mapping->host);
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
- arch/x86/kernel/cpu/perf_event_amd_ibs.c | 2 +-
+ arch/x86/kernel/cpu/perf_event_amd_ibs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
-diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
-index 989d3c215d2bc..66ca6ec09bd42 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
-@@ -555,7 +555,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
+@@ -555,7 +555,7 @@ static int perf_ibs_handle_irq(struct pe
if (event->attr.sample_type & PERF_SAMPLE_RAW)
offset_max = perf_ibs->offset_max;
else if (check_rip)
else
offset_max = 1;
do {
---
-2.20.1
-
igb-fix-constant-media-auto-sense-switching-when-no-.patch
e1000-fix-memory-leaks.patch
can-flexcan-disable-completely-the-ecc-mechanism.patch
+mm-filemap.c-don-t-initiate-writeback-if-mapping-has-no-dirty-pages.patch
+cgroup-writeback-don-t-switch-wbs-immediately-on-dead-wbs-if-the-memcg-is-dead.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
