Messages in this thread | | | Date | Sat, 10 Nov 2007 23:04:41 +0100 | From | Jiri Slaby <> | Subject | Re: [RFC 13/13] Char: nozomi, cleanup read and write |
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On 11/10/2007 05:15 PM, Adrian Bunk wrote: > On Fri, Nov 09, 2007 at 06:51:35PM -0500, Jiri Slaby wrote: >> ... >> --- a/drivers/char/nozomi.c >> +++ b/drivers/char/nozomi.c >> ... >> - if (size_bytes - i == 2) { >> + if (unlikely(size_bytes - i == 2)) { >> ... > > Please don't add likely/unlikely in drivers unless it brings a > measurable improvement.
Why? Anyway I think this is the case. The body of the then branch is executed at most once, while the else branch each time but last. If you write/read 1002 bytes, it means 250:1. ...and it's invoked from interrupt too...
regards, -- Jiri Slaby (jirislaby@gmail.com) Faculty of Informatics, Masaryk University - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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