linux-kernel - Re: slab: start_cpu_timer/cache_reap CONFIG_HOTPLUG

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]

Message-ID: <Pine.LNX.4.64.0701291346110.548@schroedinger.engr.sgi.com>
Date:	Mon, 29 Jan 2007 13:48:48 -0800 (PST)
From:	Christoph Lameter <clameter@....com>
To:	Oleg Nesterov <oleg@...sign.ru>
cc:	Ingo Molnar <mingo@...e.hu>, Srivatsa Vaddagiri <vatsa@...ibm.com>,
	"Pallipadi, Venkatesh" <venkatesh.pallipadi@...el.com>,
	Gautham shenoy <ego@...ibm.com>, Andrew Morton <akpm@...l.org>,
	linux-kernel@...r.kernel.org
Subject: Re: slab: start_cpu_timer/cache_reap CONFIG_HOTPLUG_CPU problems

On Tue, 30 Jan 2007, Oleg Nesterov wrote:

> Now we have 2 additional events, CPU_LOCK_ACQUIRE/CPU_LOCK_RELEASE,
> so cpuup_callback() can use them to lock/unlock cache_chain_mutex,
> but this is not related.

Then we wont need to do the mutex_lock/unlock in CPU_DOWN_XX 
anymore, right? Which brings us to this form of the patch:


Shutdown cache_reaper when cpu goes down

Shutdown the cache_reaper in slab.c if the cpu is brought down
and set the cache_reap.func to NULL. Otherwise hotplug shuts
down the reaper for good.

Signed-off-by: Christoph Lameter <clameter@....com>

Index: linux-2.6.20-rc6-mm2/mm/slab.c
===================================================================
--- linux-2.6.20-rc6-mm2.orig/mm/slab.c	2007-01-29 14:27:34.199229828 -0600
+++ linux-2.6.20-rc6-mm2/mm/slab.c	2007-01-29 15:47:18.293962726 -0600
@@ -1271,6 +1271,14 @@ static int __cpuinit cpuup_callback(stru
 		start_cpu_timer(cpu);
 		break;
 #ifdef CONFIG_HOTPLUG_CPU
+  	case CPU_DOWN_PREPARE:
+		/* Shutdown cache reaper */
+		cancel_rearming_delayed_work(&per_cpu(reap_work, cpu));
+		per_cpu(reap_work, cpu).work.func = NULL;
+  		break;
+  	case CPU_DOWN_FAILED:
+		start_cpu_timer(cpu);
+  		break;
 	case CPU_DEAD:
 		/*
 		 * Even if all the cpus of a node are down, we don't free the
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/