From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: mmotm 2013-06-27-16-36 uploaded (wait event common) Date: Thu, 27 Jun 2013 23:06:43 -0700 Message-ID: <51CD27F3.30104@infradead.org> References: <20130627233733.BAEB131C3BE@corp2gmr1-1.hot.corp.google.com> <51CD1F81.4040202@infradead.org> <20130627225139.798e7b00.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, Oleg Nesterov To: Andrew Morton Return-path: In-Reply-To: <20130627225139.798e7b00.akpm@linux-foundation.org> Sender: linux-next-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 06/27/13 22:51, Andrew Morton wrote: > On Thu, 27 Jun 2013 22:30:41 -0700 Randy Dunlap wrote: > >> On 06/27/13 16:37, akpm@linux-foundation.org wrote: >>> The mm-of-the-moment snapshot 2013-06-27-16-36 has been uploaded to >>> >>> http://www.ozlabs.org/~akpm/mmotm/ >>> >>> mmotm-readme.txt says >>> >>> README for mm-of-the-moment: >>> >>> http://www.ozlabs.org/~akpm/mmotm/ >>> >> >> My builds are littered with hundreds of warnings like this one: >> >> drivers/tty/tty_ioctl.c:220:6: warning: the omitted middle operand in ?: will always be 'true', suggest explicit middle operand [-Wparentheses] >> >> I guess due to this line from wait_event_common(): >> >> + __ret = __wait_no_timeout(tout) ?: (tout) ?: 1; >> > > Ah, sorry, I missed that. Had I noticed it, I would have spat it back > on taste grounds alone, it being unfit for human consumption. > > Something like this? > > --- a/include/linux/wait.h~wait-introduce-wait_event_commonwq-condition-state-timeout-fix > +++ a/include/linux/wait.h > @@ -196,7 +196,11 @@ wait_queue_head_t *bit_waitqueue(void *, > for (;;) { \ > prepare_to_wait(&wq, &__wait, state); \ > if (condition) { \ > - __ret = __wait_no_timeout(tout) ?: __tout ?: 1; \ > + __ret = __wait_no_timeout(tout); \ > + if (!__ret) \ > + __ret = __tout; \ > + if (!__ret) \ > + __ret = 1; \ > break; \ > } \ > \ > > That does reduce the number of warnings, but the wait_event_common() macro needs similar treatment. I.e., I am still getting those warnings, just not quite as many. (down from 2 per source code line to 1 per source code line which contains some kind of wait...) -- ~Randy