[PATCH] kmemleak: Mark nice +10

[Ingo Molnar <mingo@elte.hu>]

* Catalin Marinas <catalin.marinas@arm.com> wrote:

> On Wed, 2009-07-01 at 11:30 +0200, Ingo Molnar wrote:
> > * Catalin Marinas <catalin.marinas@arm.com> wrote:
> > 
> > > > The minimal fix below removes scan_yield() and adds a 
> > > > cond_resched() to the outmost (safe) place of the scanning 
> > > > thread. This solves the regression.
> > > 
> > > With CONFIG_PREEMPT disabled it won't reschedule during the bss 
> > > scanning but I don't see this as a real issue (task stacks 
> > > scanning probably takes longer anyway).
> > 
> > Yeah. I suspect one more cond_resched() could be added - i just 
> > didnt see an obvious place for it, given that scan_block() is being 
> > called with asymetric held-locks contexts.
> 
> Now that your patch was merged, I propose adding a few more 
> cond_resched() calls, useful for the !PREEMPT case:

note, please also merge the renicing fix you sent. I have it tested 
in tip:out-of-tree, attached below.

	Ingo

>From f6a529517732a9d0e1ad0cd43ad7d2d96de4a4f5 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Wed, 1 Jul 2009 10:18:57 +0100
Subject: [PATCH] kmemleak: Mark nice +10

> The background scanning thread could probably also be reniced
> to +10.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 mm/kmemleak.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e766e1d..6006553 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1039,6 +1039,7 @@ static int kmemleak_scan_thread(void *arg)
 	static int first_run = 1;
 
 	pr_info("Automatic memory scanning thread started\n");
+	set_user_nice(current, 10);
 
 	/*
 	 * Wait before the first scan to allow the system to fully initialize.