Messages in this thread | | | Date | Mon, 3 Aug 2015 17:38:20 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 00/15] trivial: Drop unlikely before IS_ERR(_OR_NULL) |
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On Fri, 31 Jul 2015 13:23:10 +0300 "Kirill A. Shutemov" <kirill@shutemov.name> wrote:
> On Fri, Jul 31, 2015 at 11:41:09AM +0200, Vlastimil Babka wrote: > > On 07/31/2015 10:38 AM, Viresh Kumar wrote: > > >Hi, > > > > > >This cleans up the usage of IS_ERR(_OR_NULL)(), where the callers have > > >added additional unlikely compiler flag to them. It also fixes the > > >definition of IS_ERR_OR_NULL(), to use unlikely for all checks it does. > > > > [+CC Steven Rostedt] > > > > Any idea what the compiler does in the case of > > "if (likely(IS_ERR(...)))"? There are apparently such cases in the source. > > We have two cases in code: > > drivers/rtc/rtc-gemini.c: if (likely(IS_ERR(rtc->rtc_dev))) > drivers/staging/lustre/lustre/obdclass/lu_object.c: if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) { > > The first one is mistake, I think. Or do we expect rtc_device_register() > to fail? > > The second is redundant. "if (PTR_ERR(shadow) == -ENOENT)" should do the > job. >
Yep, those look like bugs to me.
-- Steve
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