34 lines
1.2 KiB
Diff
34 lines
1.2 KiB
Diff
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From c28e07715162bb1e1567a935b45772ca85a5267c 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] fs: jbd2: pull your plug when waiting for space
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/3.14/patches-3.14.0-rt1.tar.xz
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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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Cc: stable-rt@vger.kernel.org
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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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--- a/fs/jbd2/checkpoint.c
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+++ b/fs/jbd2/checkpoint.c
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@@ -125,6 +125,8 @@ void __jbd2_log_wait_for_space(journal_t
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if (journal->j_flags & JBD2_ABORT)
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return;
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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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