Re: [patch/backport] CFS scheduler, -v22, for v2.6.23-rc8,v2.6.22.8, v2.6.21.7, v2.6.20.20

From: Ingo Molnar
Date: Wed Sep 26 2007 - 09:48:24 EST



* S.ÃaÄlar Onur <caglar@xxxxxxxxxxxxx> wrote:

> Compilation [against 2.6.20.20] fails with
>
> buildfarm linux-2.6.20 # make
> CHK include/linux/version.h
> CHK include/linux/utsrelease.h
> CHK include/linux/compile.h
> CC kernel/sched.o
> In file included from kernel/sched.c:850:
> kernel/sched_fair.c:49: error: sysctl_sched_nr_latency causes a section type
> conflict
> make[1]: *** [kernel/sched.o] Error 1
> make: *** [kernel] Error 2

oops, indeed! This happens with certain .config combinations only and it
didnt trigger on mine.

> @kernel/sched_fair.c
> -const_debug unsigned int sysctl_sched_nr_latency __read_mostly = 20;
> +const_debug unsigned int sysctl_sched_nr_latency = 20;
>
> seems solve that issue but i'm not sure this is the right thing to do
> or not :)

your fix is the right one - and i've updated the patches with this small
fix. Anyone who hits this issue should re-download the same patch once
more, or should apply the small patch below.

Ingo

Index: linux/kernel/sched_fair.c
===================================================================
--- linux.orig/kernel/sched_fair.c
+++ linux/kernel/sched_fair.c
@@ -46,7 +46,7 @@ const_debug unsigned int sysctl_sched_ch
* Minimal preemption granularity for CPU-bound tasks:
* (default: 2 msec, units: nanoseconds)
*/
-const_debug unsigned int sysctl_sched_nr_latency __read_mostly = 20;
+const_debug unsigned int sysctl_sched_nr_latency = 20;

/*
* sys_sched_yield() compat mode
-
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