2014-12-01 14:39:35

by Prarit Bhargava

Subject: [PATCH] tools, cpupower, fix return checks for sysfs_get_idlestate_count()

Red Hat and Fedora use a bug reporting tool that gathers data about
"broken" systems called sosreport. Among other things, it includes the
output of 'cpupower idle-info'. Executing 'cpupower idle-info' on a
system that has cpuidle disabled via 'cpuidle.off=1' results in a 300
second hang in the cpupower application.

ie)
[root@intel-brickland-05]# cpupower idle-info
Could not determine cpuidle driver

Analyzing CPU 0:
Number of idle states: -19
[hang]

The problem is that the cpupower code only checks for a zero return from
sysfs_get_idlestate_count(). The function can return -ENODEV (-19) as
above. This patch fixes callers to sysfs_get_idlestate_count() to check
the right return values.

Cc: Thomas Renninger <[email protected]>
Cc: [email protected]
Signed-off-by: Prarit Bhargava <[email protected]>
---
tools/power/cpupower/utils/cpuidle-info.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/power/cpupower/utils/cpuidle-info.c b/tools/power/cpupower/utils/cpuidle-info.c
index 75e66de..458d69b 100644
--- a/tools/power/cpupower/utils/cpuidle-info.c
+++ b/tools/power/cpupower/utils/cpuidle-info.c
@@ -22,13 +22,13 @@

static void cpuidle_cpu_output(unsigned int cpu, int verbose)
{
- unsigned int idlestates, idlestate;
+ int idlestates, idlestate;
char *tmp;

printf(_ ("Analyzing CPU %d:\n"), cpu);

idlestates = sysfs_get_idlestate_count(cpu);
- if (idlestates == 0) {
+ if (idlestates < 1) {
printf(_("CPU %u: No idle states\n"), cpu);
return;
}
@@ -100,10 +100,10 @@ static void cpuidle_general_output(void)
static void proc_cpuidle_cpu_output(unsigned int cpu)
{
long max_allowed_cstate = 2000000000;
- unsigned int cstate, cstates;
+ int cstate, cstates;

cstates = sysfs_get_idlestate_count(cpu);
- if (cstates == 0) {
+ if (cstates < 1) {
printf(_("CPU %u: No C-states info\n"), cpu);
return;
}
--
1.7.9.3

2014-12-03 18:25:31

by Thomas Renninger

Subject: Re: [PATCH] tools, cpupower, fix return checks for sysfs_get_idlestate_count()

On Monday, December 01, 2014 09:39:22 AM Prarit Bhargava wrote:
> Red Hat and Fedora use a bug reporting tool that gathers data about
> "broken" systems called sosreport. Among other things, it includes the
> output of 'cpupower idle-info'. Executing 'cpupower idle-info' on a
> system that has cpuidle disabled via 'cpuidle.off=1' results in a 300
> second hang in the cpupower application.
>
> ie)
> [root@intel-brickland-05]# cpupower idle-info
> Could not determine cpuidle driver
>
> Analyzing CPU 0:
> Number of idle states: -19
> [hang]
>
> The problem is that the cpupower code only checks for a zero return from
> sysfs_get_idlestate_count(). The function can return -ENODEV (-19) as
> above. This patch fixes callers to sysfs_get_idlestate_count() to check
> the right return values.
>
> Cc: Thomas Renninger <[email protected]>
> Cc: [email protected]
> Signed-off-by: Prarit Bhargava <[email protected]>

Signed-off-by: Thomas Renninger <[email protected]>