From: Matthias Kaehlcke Date: Mon, 30 Oct 2017 18:08:16 +0000 (-0700) Subject: sched/sysctl: Fix attributes of some extern declarations X-Git-Tag: v4.9.161~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9eea082f762f7f71c0d0373d821b1aac22f719e3;p=platform%2Fkernel%2Flinux-amlogic.git sched/sysctl: Fix attributes of some extern declarations commit a9903f04e0a4ea522d959c2f287cdf0ab029e324 upstream. The definition of sysctl_sched_migration_cost, sysctl_sched_nr_migrate and sysctl_sched_time_avg includes the attribute const_debug. This attribute is not part of the extern declaration of these variables in include/linux/sched/sysctl.h, while it is in kernel/sched/sched.h, and as a result Clang generates warnings like this: kernel/sched/sched.h:1618:33: warning: section attribute is specified on redeclared variable [-Wsection] extern const_debug unsigned int sysctl_sched_time_avg; ^ ./include/linux/sched/sysctl.h:42:21: note: previous declaration is here extern unsigned int sysctl_sched_time_avg; The header only declares the variables when CONFIG_SCHED_DEBUG is defined, therefore it is not necessary to duplicate the definition of const_debug. Instead we can use the attribute __read_mostly, which is the expansion of const_debug when CONFIG_SCHED_DEBUG=y is set. Signed-off-by: Matthias Kaehlcke Reviewed-by: Nick Desaulniers Cc: Douglas Anderson Cc: Guenter Roeck Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Shile Zhang Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20171030180816.170850-1-mka@chromium.org Signed-off-by: Ingo Molnar [nc: Backport to 4.9] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman --- diff --git a/include/linux/sched/sysctl.h b/include/linux/sched/sysctl.h index 22db1e63707e..05e8b6e4edcb 100644 --- a/include/linux/sched/sysctl.h +++ b/include/linux/sched/sysctl.h @@ -33,9 +33,9 @@ extern unsigned int sysctl_numa_balancing_scan_period_max; extern unsigned int sysctl_numa_balancing_scan_size; #ifdef CONFIG_SCHED_DEBUG -extern unsigned int sysctl_sched_migration_cost; -extern unsigned int sysctl_sched_nr_migrate; -extern unsigned int sysctl_sched_time_avg; +extern __read_mostly unsigned int sysctl_sched_migration_cost; +extern __read_mostly unsigned int sysctl_sched_nr_migrate; +extern __read_mostly unsigned int sysctl_sched_time_avg; extern unsigned int sysctl_sched_shares_window; int sched_proc_update_handler(struct ctl_table *table, int write,