From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Sender: =?UTF-8?Q?Micha=C5=82_Nazarewicz?= Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes To: linux-kernel@vger.kernel.org, "Gilad Ben-Yossef" Subject: Re: [RFC PATCH 0/9] Remove useless on_each_cpu return value References: <1325600353-10895-1-git-send-email-gilad@benyossef.com> Date: Tue, 03 Jan 2012 15:25:49 +0100 MIME-Version: 1.0 From: "Michal Nazarewicz" Message-ID: In-Reply-To: <1325600353-10895-1-git-send-email-gilad@benyossef.com> Cc: linux-ia64@vger.kernel.org, David Airlie , Will Deacon , dri-devel@lists.freedesktop.org, Paul Mackerras , "H. Peter Anvin" , Russell King , x86@kernel.org, Ingo Molnar , Arnaldo Carvalho de Melo , Matt Turner , Fenghua Yu , Peter Zijlstra , devicetree-discuss@lists.ozlabs.org, Rob Herring , Ivan Kokshaysky , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Richard Henderson , Tony Luck , linux-alpha@vger.kernel.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 03 Jan 2012 15:19:04 +0100, Gilad Ben-Yossef wrote: > on_each_cpu() returns as its own return value the return value of > smp_call_function(). smp_call_function() in turn returns a hard > coded value of zero. > > Some callers to on_each_cpu() waste cycles and bloat code space > by checking the return value to on_each_cpu(), probably for > historical reasons. > > This patch set refactors callers to not test on_each_cpu() > (fixed) return value and then refactors on_each_cpu to > return void to avoid confusing future users. > > In other words, this patch aims to delete 18 source code lines > while not changing any functionality :-) > > I tested as best as I could the x86 changes and compiled some > of the others, but I don't have access to all the needed hardware > for testing. Reviewers and testers welcome! Other then the lack of Signed-off-by in the patches, looks good to me, even though personally I'd choose a bottom-up approach, ie. make smp_call_function() return void and from that conclude that on_each_cpu() can return void. With those patches, we have a situation,= where smp_call_function() has a return value which is then lost for no immediately apparent reason lost in on_each_cpu(). -- = Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=3D./ `o ..o | Computer Science, Micha=C5=82 =E2=80=9Cmina86=E2=80=9D Nazarewicz= (o o) ooo +------------------ooO--(_)--Ooo--