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43 lines
1.6 KiB
Diff
43 lines
1.6 KiB
Diff
From a51f1d6202dd947639db67db099924528f58a22b Mon Sep 17 00:00:00 2001
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From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
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Date: Thu, 18 Jan 2018 15:42:09 -0500
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Subject: [PATCH 113/436] ring-buffer: Fix duplicate results in mapping context
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to bits in recursive lock
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In bringing back the context checks, the code checks first if its normal
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(non-interrupt) context, and then for NMI then IRQ then softirq. The final
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check is redundant. Since the if branch is only hit if the context is one of
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NMI, IRQ, or SOFTIRQ, if it's not NMI or IRQ there's no reason to check if
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it is SOFTIRQ. The current code returns the same result even if its not a
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SOFTIRQ. Which is confusing.
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pc & SOFTIRQ_OFFSET ? 2 : RB_CTX_SOFTIRQ
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Is redundant as RB_CTX_SOFTIRQ *is* 2!
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Fixes: a0e3a18f4baf ("ring-buffer: Bring back context level recursive checks")
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Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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(cherry picked from commit 0164e0d7e803af3ee1c63770978c728f8778ad01)
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/trace/ring_buffer.c | 3 +--
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1 file changed, 1 insertion(+), 2 deletions(-)
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diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
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index b7cda4701ab3..be296c38893f 100644
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--- a/kernel/trace/ring_buffer.c
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+++ b/kernel/trace/ring_buffer.c
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@@ -2635,8 +2635,7 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
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bit = RB_CTX_NORMAL;
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else
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bit = pc & NMI_MASK ? RB_CTX_NMI :
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- pc & HARDIRQ_MASK ? RB_CTX_IRQ :
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- pc & SOFTIRQ_OFFSET ? 2 : RB_CTX_SOFTIRQ;
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+ pc & HARDIRQ_MASK ? RB_CTX_IRQ : RB_CTX_SOFTIRQ;
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if (unlikely(val & (1 << bit)))
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return 1;
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--
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2.19.1
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