linux-kernel - [PATCH v2 2/4] perf: Simplify group_sched

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Date:   Thu, 29 Oct 2020 17:27:21 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     mingo@...nel.org, acme@...nel.org, mark.rutland@....com,
        alexander.shishkin@...ux.intel.com, jolsa@...hat.com,
        namhyung@...nel.org
Cc:     linux-kernel@...r.kernel.org, eranian@...gle.com,
        ak@...ux.intel.com, peterz@...radead.org
Subject: [PATCH v2 2/4] perf: Simplify group_sched_in()

Collate the error paths. Code duplication only leads to divergence and
extra bugs.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
---
 kernel/events/core.c |   10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2580,11 +2580,8 @@ group_sched_in(struct perf_event *group_
 
 	pmu->start_txn(pmu, PERF_PMU_TXN_ADD);
 
-	if (event_sched_in(group_event, cpuctx, ctx)) {
-		pmu->cancel_txn(pmu);
-		perf_mux_hrtimer_restart(cpuctx);
-		return -EAGAIN;
-	}
+	if (event_sched_in(group_event, cpuctx, ctx))
+		goto error;
 
 	/*
 	 * Schedule in siblings as one group (if any):
@@ -2613,10 +2610,9 @@ group_sched_in(struct perf_event *group_
 	}
 	event_sched_out(group_event, cpuctx, ctx);
 
+error:
 	pmu->cancel_txn(pmu);
-
 	perf_mux_hrtimer_restart(cpuctx);
-
 	return -EAGAIN;
 }