[v4,1/2] power: fix pstate base frequency handling
Checks
Commit Message
Previous fix for base frequency handling in pstate mode introduced a
couple of issues:
- When base_frequency file does not exist, it simply bails out because
of what appears to be accidental addition of FOPEN_OR_ERR_RET. This is
incorrect, as absence of this file is not fatal and is in fact
expected on kernel versions earlier than 5.3
- When base_frequency file does exist, it gets opened, but never gets
closed, resulting in a resource leak
Both issues also manifest themselves as Coverity defects (dead code, and
a resource leak), so this fix addresses both.
Fixes: 4db9587bbf72 ("power: check sysfs base frequency")
Cc: david.hunt@intel.com
Coverity issue: 369693
Coverity issue: 369694
Bugzilla ID: 668
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
---
lib/librte_power/power_pstate_cpufreq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Comments
On 02-Apr-21 10:26 AM, Anatoly Burakov wrote:
> Previous fix for base frequency handling in pstate mode introduced a
> couple of issues:
>
> - When base_frequency file does not exist, it simply bails out because
> of what appears to be accidental addition of FOPEN_OR_ERR_RET. This is
> incorrect, as absence of this file is not fatal and is in fact
> expected on kernel versions earlier than 5.3
> - When base_frequency file does exist, it gets opened, but never gets
> closed, resulting in a resource leak
>
> Both issues also manifest themselves as Coverity defects (dead code, and
> a resource leak), so this fix addresses both.
>
> Fixes: 4db9587bbf72 ("power: check sysfs base frequency")
> Cc: david.hunt@intel.com
>
> Coverity issue: 369693
> Coverity issue: 369694
> Bugzilla ID: 668
>
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> ---
For some reason git notes got lost on format-patch.
v3:
- Split refactor from bugfixes
v4:
- v3 was erroneously "fixing" handling of base max rather than base
frequency
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Burakov, Anatoly
> Sent: Friday, April 2, 2021 10:36 AM
> To: dev@dpdk.org
> Cc: Hunt, David <david.hunt@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v4 1/2] power: fix pstate base frequency
> handling
>
> On 02-Apr-21 10:26 AM, Anatoly Burakov wrote:
> > Previous fix for base frequency handling in pstate mode introduced a
> > couple of issues:
> >
> > - When base_frequency file does not exist, it simply bails out because
> > of what appears to be accidental addition of FOPEN_OR_ERR_RET. This is
> > incorrect, as absence of this file is not fatal and is in fact
> > expected on kernel versions earlier than 5.3
> > - When base_frequency file does exist, it gets opened, but never gets
> > closed, resulting in a resource leak
> >
> > Both issues also manifest themselves as Coverity defects (dead code,
> > and a resource leak), so this fix addresses both.
> > Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
> > ---
Acked-by: Reshma Pattan <reshma.pattan@intel.com>
@@ -206,7 +206,6 @@ power_init_for_setting_freq(struct pstate_power_info *pi)
pi->lcore_id);
f_base = fopen(fullpath_base, "r");
- FOPEN_OR_ERR_RET(f_base, -1);
if (f_base == NULL) {
/* No sysfs base_frequency, that's OK, continue without */
base_ratio = 0;
@@ -221,6 +220,7 @@ power_init_for_setting_freq(struct pstate_power_info *pi)
base_ratio = strtoul(buf_base, NULL, POWER_CONVERT_TO_DECIMAL)
/ BUS_FREQ;
+ fclose(f_base);
}
/* Add MSR read to detect turbo status */