38 lines
1.2 KiB
Diff
38 lines
1.2 KiB
Diff
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From 4b386fb672a366ec2fe2929da01caf71dde172d0 Mon Sep 17 00:00:00 2001
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Date: Mon, 17 Feb 2014 17:30:03 +0100
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Subject: [PATCH 202/365] fs: jbd2: pull your plug when waiting for space
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Two cps in parallel managed to stall the the ext4 fs. It seems that
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journal code is either waiting for locks or sleeping waiting for
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something to happen. This seems similar to what Mike observed on ext3,
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here is his description:
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|With an -rt kernel, and a heavy sync IO load, tasks can jam
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|up on journal locks without unplugging, which can lead to
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|terminal IO starvation. Unplug and schedule when waiting
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|for space.
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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fs/jbd2/checkpoint.c | 2 ++
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1 file changed, 2 insertions(+)
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diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
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index addb0784dd1c..bd8ab9c28869 100644
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--- a/fs/jbd2/checkpoint.c
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+++ b/fs/jbd2/checkpoint.c
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@@ -116,6 +116,8 @@ void __jbd2_log_wait_for_space(journal_t *journal)
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nblocks = jbd2_space_needed(journal);
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while (jbd2_log_space_left(journal) < nblocks) {
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write_unlock(&journal->j_state_lock);
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+ if (current->plug)
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+ io_schedule();
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mutex_lock(&journal->j_checkpoint_mutex);
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/*
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--
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2.28.0
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