From: Oleg Nesterov <oleg@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/6] sched, wait: Collapse __wait_event macros -v4
Date: Tue, 1 Oct 2013 16:09:40 +0200 [thread overview]
Message-ID: <20131001140940.GA32328@redhat.com> (raw)
In-Reply-To: <20130930181358.GA29544@redhat.com>
On 09/30, Oleg Nesterov wrote:
>
> On 09/30, Peter Zijlstra wrote:
> >
> > On Mon, Sep 30, 2013 at 07:40:54PM +0200, Oleg Nesterov wrote:
> > > Once again, of course I do not blame this series, but
> > > wait_event_timeout(wq, true, 0) still returns 0.
> >
> > So we have:
> >
> > [...snip...]
>
> > So wait_event_timeout(wq, true, 0) turns into:
>
> Not really, because of fast-path check,
>
> #define wait_event_timeout(wq, condition, timeout) \
> ({ \
> long __ret = timeout; \
> if (!(condition)) \
> __ret = __wait_event_timeout(wq, condition, timeout); \
> __ret; \
> })
>
> we do not even call __wait_event_timeout() if "condition" is already
> true at the start.
But somehow I didn't realize that ___wait_cond_timeout() can be used
as is, so the simple patch below should work?
Oleg.
--- x/include/linux/wait.h
+++ x/include/linux/wait.h
@@ -270,7 +270,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
@@ -328,7 +328,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
@@ -770,7 +770,7 @@ do { \
timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, timeout); \
__ret; \
next prev parent reply other threads:[~2013-10-01 14:16 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-30 15:22 [PATCH 0/6] sched, wait: Collapse __wait_event macros -v4 Peter Zijlstra
2013-09-30 15:22 ` [PATCH 1/6] sched, wait: Make the signal_pending() checks consistent Peter Zijlstra
2013-09-30 15:22 ` [PATCH 2/6] sched, wait: Change timeout logic Peter Zijlstra
2013-09-30 15:48 ` Linus Torvalds
2013-09-30 16:09 ` Peter Zijlstra
2013-09-30 15:22 ` [PATCH 3/6] sched, wait: Change the wait_exclusive control flow Peter Zijlstra
2013-09-30 15:22 ` [PATCH 4/6] sched, wait: Collapse __wait_event macros Peter Zijlstra
2013-09-30 15:22 ` [PATCH 5/6] sched, wait: Also use ___wait_event() for __wait_event_hrtimeout Peter Zijlstra
2013-09-30 15:22 ` [PATCH 6/6] sched, wait: Make the __wait_event*() interface more friendly Peter Zijlstra
2013-10-01 6:39 ` Ingo Molnar
2013-09-30 15:50 ` [PATCH 0/6] sched, wait: Collapse __wait_event macros -v4 Linus Torvalds
2013-09-30 16:11 ` Peter Zijlstra
2013-09-30 17:40 ` Oleg Nesterov
2013-09-30 18:00 ` Oleg Nesterov
2013-09-30 18:09 ` Peter Zijlstra
2013-09-30 18:13 ` Oleg Nesterov
2013-10-01 14:09 ` Oleg Nesterov [this message]
2013-10-01 14:39 ` Peter Zijlstra
2013-10-01 15:16 ` Oleg Nesterov
2013-10-01 17:01 ` [RFC] introduce prepare_to_wait_event() Oleg Nesterov
2013-10-01 17:25 ` Peter Zijlstra
2013-10-01 17:33 ` Oleg Nesterov
2013-10-01 17:44 ` Peter Zijlstra
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=20131001140940.GA32328@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.