linux-kernel - [tip:smp/hotplug] block/softirq: Convert to hotplug state machine

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 19 Sep 2016 12:55:08 -0700
From:   tip-bot for Sebastian Andrzej Siewior <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, hpa@...or.com, peterz@...radead.org,
        tglx@...utronix.de, mingo@...nel.org, bigeasy@...utronix.de,
        axboe@...nel.dk
Subject: [tip:smp/hotplug] block/softirq: Convert to hotplug state machine

Commit-ID:  9a659f43dfea27cca423d4e80809be447f4c9ce7
Gitweb:     http://git.kernel.org/tip/9a659f43dfea27cca423d4e80809be447f4c9ce7
Author:     Sebastian Andrzej Siewior <bigeasy@...utronix.de>
AuthorDate: Tue, 6 Sep 2016 19:04:44 +0200
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Mon, 19 Sep 2016 21:44:28 +0200

block/softirq: Convert to hotplug state machine

Install the callbacks via the state machine.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: rt@...utronix.de
Link: http://lkml.kernel.org/r/20160906170457.32393-9-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>

---
 block/blk-softirq.c        | 27 ++++++++++-----------------
 include/linux/cpuhotplug.h |  1 +
 2 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index 53b1737..96631e6 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -78,30 +78,21 @@ static int raise_blk_irq(int cpu, struct request *rq)
 }
 #endif
 
-static int blk_cpu_notify(struct notifier_block *self, unsigned long action,
-			  void *hcpu)
+static int blk_softirq_cpu_dead(unsigned int cpu)
 {
 	/*
 	 * If a CPU goes away, splice its entries to the current CPU
 	 * and trigger a run of the softirq
 	 */
-	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
-		int cpu = (unsigned long) hcpu;
-
-		local_irq_disable();
-		list_splice_init(&per_cpu(blk_cpu_done, cpu),
-				 this_cpu_ptr(&blk_cpu_done));
-		raise_softirq_irqoff(BLOCK_SOFTIRQ);
-		local_irq_enable();
-	}
+	local_irq_disable();
+	list_splice_init(&per_cpu(blk_cpu_done, cpu),
+			 this_cpu_ptr(&blk_cpu_done));
+	raise_softirq_irqoff(BLOCK_SOFTIRQ);
+	local_irq_enable();
 
-	return NOTIFY_OK;
+	return 0;
 }
 
-static struct notifier_block blk_cpu_notifier = {
-	.notifier_call	= blk_cpu_notify,
-};
-
 void __blk_complete_request(struct request *req)
 {
 	int ccpu, cpu;
@@ -180,7 +171,9 @@ static __init int blk_softirq_init(void)
 		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
 
 	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
-	register_hotcpu_notifier(&blk_cpu_notifier);
+	cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
+				  "block/softirq:dead", NULL,
+				  blk_softirq_cpu_dead);
 	return 0;
 }
 subsys_initcall(blk_softirq_init);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 2ca7b34..d4274d5 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -23,6 +23,7 @@ enum cpuhp_state {
 	CPUHP_ARM64_FPSIMD_DEAD,
 	CPUHP_ARM_OMAP_WAKE_DEAD,
 	CPUHP_IRQ_POLL_DEAD,
+	CPUHP_BLOCK_SOFTIRQ_DEAD,
 	CPUHP_WORKQUEUE_PREP,
 	CPUHP_POWER_NUMA_PREPARE,
 	CPUHP_HRTIMERS_PREPARE,