From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM list <linux-pm@vger.kernel.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"'Daniel Lezcano'" <daniel.lezcano@linaro.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 2/2] cpuidle / menu: Return error code if there are no suitable states
Date: Sun, 27 Apr 2014 14:55:30 +0200 [thread overview]
Message-ID: <6832089.A5AOPipfbA@vostro.rjw.lan> (raw)
In-Reply-To: <2471963.urOyfY8mOG@vostro.rjw.lan>
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If there is a PM QoS latency limit and all of the sufficiently shallow
C-states are disabled, the cpuidle menu governor returns 0 which on
some systems is CPUIDLE_DRIVER_STATE_START and shouldn't be returned
if that C-state has been disabled.
Fix the issue by modifying the menu governor to return an error code
in such situations.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpuidle/governors/menu.c | 2 +-
include/linux/cpuidle.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/cpuidle/governors/menu.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/governors/menu.c
+++ linux-pm/drivers/cpuidle/governors/menu.c
@@ -296,7 +296,7 @@ static int menu_select(struct cpuidle_dr
data->needs_update = 0;
}
- data->last_state_idx = 0;
+ data->last_state_idx = CPUIDLE_DRIVER_STATE_POLL;
/* Special case when user has set very strict latency requirement */
if (unlikely(latency_req == 0))
Index: linux-pm/include/linux/cpuidle.h
===================================================================
--- linux-pm.orig/include/linux/cpuidle.h
+++ linux-pm/include/linux/cpuidle.h
@@ -217,8 +217,10 @@ static inline int cpuidle_register_gover
#ifdef CONFIG_ARCH_HAS_CPU_RELAX
#define CPUIDLE_DRIVER_STATE_START 1
+#define CPUIDLE_DRIVER_STATE_POLL 0
#else
#define CPUIDLE_DRIVER_STATE_START 0
+#define CPUIDLE_DRIVER_STATE_POLL (-ENXIO)
#endif
#endif /* _LINUX_CPUIDLE_H */
next prev parent reply other threads:[~2014-04-27 12:39 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-27 12:53 [PATCH 0/2] cpuidle: Avoid returning a disabled C-state from menu governor Rafael J. Wysocki
2014-04-27 12:54 ` [PATCH 1/2] cpuidle: Combine cpuidle_enabled() with cpuidle_select() Rafael J. Wysocki
2014-04-27 12:55 ` Rafael J. Wysocki [this message]
2014-04-28 11:14 ` [PATCH 2/2] cpuidle / menu: Return error code if there are no suitable states Daniel Lezcano
2014-04-28 23:28 ` Rafael J. Wysocki
2014-04-29 23:16 ` Rafael J. Wysocki
2014-05-02 8:47 ` Daniel Lezcano
2014-05-02 12:20 ` Rafael J. Wysocki
2014-05-02 13:19 ` Daniel Lezcano
2014-05-04 22:39 ` Rafael J. Wysocki
2014-04-30 12:40 ` Daniel Lezcano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6832089.A5AOPipfbA@vostro.rjw.lan \
--to=rjw@rjwysocki.net \
--cc=daniel.lezcano@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).