From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: Re: [PATCH V2] tipc: Use bsearch library function Date: Sat, 16 Sep 2017 02:58:28 -0700 Message-ID: <1505555908.16316.5.camel@perches.com> References: <20170911.143025.555018840006192902.davem@davemloft.net> <20170916075036.28676-1-thomas@m3y3r.de> <16128f5e-66ff-b6ec-c0e1-74ea08c212b0@windriver.com> <1505553970.16316.1.camel@perches.com> <64ee51ce-eb7e-ac1c-56a9-9481f6f80b35@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit To: Ying Xue , Thomas Meyer , jon.maloy@ericsson.com, netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, davem@davemloft.net Return-path: In-Reply-To: <64ee51ce-eb7e-ac1c-56a9-9481f6f80b35@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sat, 2017-09-16 at 17:36 +0800, Ying Xue wrote: > On 09/16/2017 05:26 PM, Joe Perches wrote: > > On Sat, 2017-09-16 at 17:02 +0800, Ying Xue wrote: > > > On 09/16/2017 03:50 PM, Thomas Meyer wrote: > > > > Use common library function rather than explicitly coding > > > > some variant of it yourself. > > > > > > > > Signed-off-by: Thomas Meyer > > > > > > Acked-by: Ying Xue > > > > Are you sure you want to do this? > > > > Note the comment above nameseq_find_subseq > > > > * Very time-critical, so binary searches through sub-sequence array. > > > > What impact does this change have on performance? > > Sorry, I couldn't see any essential difference between this new > implementation and the original one except that the former tries to use > the library function - bsearch() to replace the original binary search > algorithm implemented in TIPC itself. Therefore, I don't think the > change will have a big impact on performance. > > If I miss something, please let me know. Comparison via a function pointer in bsearch is slower than direct code without the function call overhead.