From b3da2a73ff5a2953a4ad8ebbf0aa7e6965ff9de2 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 24 Oct 2007 18:23:50 +0200 Subject: [PATCH] sched: document profile=sleep requiring CONFIG_SCHEDSTATS profile=sleep only works if CONFIG_SCHEDSTATS is set. This patch notes the limitation in Documentation/kernel-parameters.txt and prints a warning at boot-time if profile=sleep is used without CONFIG_SCHEDSTAT. Signed-off-by: Mel Gorman Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 3 ++- kernel/profile.c | 5 +++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a13d69b221..8ae5fac08d 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1444,7 +1444,8 @@ and is between 256 and 4096 characters. It is defined in the file Param: "schedule" - profile schedule points. Param: - step/bucket size as a power of 2 for statistical time based profiling. - Param: "sleep" - profile D-state sleeping (millisecs) + Param: "sleep" - profile D-state sleeping (millisecs). + Requires CONFIG_SCHEDSTATS Param: "kvm" - profile VM exits. processor.max_cstate= [HW,ACPI] diff --git a/kernel/profile.c b/kernel/profile.c index 631b75c25d..5e95330e51 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -60,6 +60,7 @@ static int __init profile_setup(char * str) int par; if (!strncmp(str, sleepstr, strlen(sleepstr))) { +#ifdef CONFIG_SCHEDSTATS prof_on = SLEEP_PROFILING; if (str[strlen(sleepstr)] == ',') str += strlen(sleepstr) + 1; @@ -68,6 +69,10 @@ static int __init profile_setup(char * str) printk(KERN_INFO "kernel sleep profiling enabled (shift: %ld)\n", prof_shift); +#else + printk(KERN_WARNING + "kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); +#endif /* CONFIG_SCHEDSTATS */ } else if (!strncmp(str, schedstr, strlen(schedstr))) { prof_on = SCHED_PROFILING; if (str[strlen(schedstr)] == ',') -- 2.39.5