linux-kernel - [PATCH 1/9] perf: Remove redundant parent context check from context

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Date:	Mon, 25 Aug 2014 16:45:35 +0200
From:	Jiri Olsa <jolsa@...nel.org>
To:	linux-kernel@...r.kernel.org
Cc:	Jiri Olsa <jolsa@...nel.org>, Andi Kleen <andi@...stfloor.org>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Corey Ashford <cjashfor@...ux.vnet.ibm.com>,
	David Ahern <dsahern@...il.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Ingo Molnar <mingo@...nel.org>,
	"Jen-Cheng(Tommy) Huang" <tommy24@...ech.edu>,
	Namhyung Kim <namhyung@...nel.org>,
	Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Stephane Eranian <eranian@...gle.com>
Subject: [PATCH 1/9] perf: Remove redundant parent context check from context_equiv

As described in commit:
  1f9a7268c67f perf: Do not allow optimized switch for non-cloned events
we dont allow optimized switch for non cloned contexts.

There's no need now to check if one of the context is parent
of the other in context_equiv function.

Cc: Andi Kleen <andi@...stfloor.org>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Corey Ashford <cjashfor@...ux.vnet.ibm.com>
Cc: David Ahern <dsahern@...il.com>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Jen-Cheng(Tommy) Huang <tommy24@...ech.edu>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Stephane Eranian <eranian@...gle.com>
Signed-off-by: Jiri Olsa <jolsa@...nel.org>
---
 kernel/events/core.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d8cb4d21a346..4ad4ba2bc106 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2257,14 +2257,6 @@ static int context_equiv(struct perf_event_context *ctx1,
 	if (ctx1->pin_count || ctx2->pin_count)
 		return 0;
 
-	/* If ctx1 is the parent of ctx2 */
-	if (ctx1 == ctx2->parent_ctx && ctx1->generation == ctx2->parent_gen)
-		return 1;
-
-	/* If ctx2 is the parent of ctx1 */
-	if (ctx1->parent_ctx == ctx2 && ctx1->parent_gen == ctx2->generation)
-		return 1;
-
 	/*
 	 * If ctx1 and ctx2 have the same parent; we flatten the parent
 	 * hierarchy, see perf_event_init_context().
-- 
1.8.3.1

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