From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: [PATCH 09/14] xen: events: Remove redundant check on unsigned variable Date: Fri, 16 Nov 2012 08:53:21 -0800 Message-ID: References: <1353048646-10935-1-git-send-email-tushar.behera@linaro.org> <1353048646-10935-10-git-send-email-tushar.behera@linaro.org> <20121116160923.GP22320@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7639547959690164149==" Return-path: In-Reply-To: <20121116160923.GP22320@phenom.dumpdata.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Konrad Rzeszutek Wilk , Tushar Behera Cc: xen-devel@lists.xensource.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, patches@linaro.org List-Id: xen-devel@lists.xenproject.org --===============7639547959690164149== Content-Type: multipart/alternative; boundary="----I3LDVZ2VLUSA4GSWOKOQ023V3XCOJH" ------I3LDVZ2VLUSA4GSWOKOQ023V3XCOJH Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To be honest I'd nack this kind of patch. The test is only redundant in the most trivial sense that the compiler can easily optimise away. The point of the test is to make sure that the range is OK even if the type subsequently becomes signed (to hold a -ve error, for example). J Konrad Rzeszutek Wilk wrote: >On Fri, Nov 16, 2012 at 12:20:41PM +0530, Tushar Behera wrote: >> No need to check whether unsigned variable is less than 0. >> >> CC: Konrad Rzeszutek Wilk > >Acked-by: Konrad Rzeszutek Wilk > >> CC: Jeremy Fitzhardinge >> CC: xen-devel@lists.xensource.com >> CC: virtualization@lists.linux-foundation.org >> Signed-off-by: Tushar Behera >> --- >> drivers/xen/events.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/drivers/xen/events.c b/drivers/xen/events.c >> index 4293c57..cadd7d1 100644 >> --- a/drivers/xen/events.c >> +++ b/drivers/xen/events.c >> @@ -216,7 +216,7 @@ static void xen_irq_info_pirq_init(unsigned irq, >> */ >> static unsigned int evtchn_from_irq(unsigned irq) >> { >> - if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", >irq))) >> + if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq))) >> return 0; >> >> return info_for_irq(irq)->evtchn; >> -- >> 1.7.4.1 -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. ------I3LDVZ2VLUSA4GSWOKOQ023V3XCOJH Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: 8bit To be honest I'd nack this kind of patch. The test is only redundant in the most trivial sense that the compiler can easily optimise away. The point of the test is to make sure that the range is OK even if the type subsequently becomes signed (to hold a -ve error, for example).

J

Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
On Fri, Nov 16, 2012 at 12:20:41PM +0530, Tushar Behera wrote:
No need to check whether unsigned variable is less than 0.

CC: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

CC: Jeremy Fitzhardinge <jeremy@goop.org>
CC: xen-devel@lists.xensource.com
CC: virtualization@lists.linux-foundation.org
Signed-off-by: Tushar Behera <tu
 shar.behera@linaro.org>
---
drivers/xen/events.c |    2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 4293c57..cadd7d1 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -216,7 +216,7 @@ static void xen_irq_info_pirq_init(unsigned irq,
*/
static unsigned int evtchn_from_irq(unsigned irq)
{
- if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
+ if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq)))
  return 0;

 return info_for_irq(irq)->evtchn;
-- 
1.7.4.1


--
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