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!
CC: Michal Nazarewicz mina86@mina86.com CC: David Airlie airlied@linux.ie CC: dri-devel@lists.freedesktop.org CC: Benjamin Herrenschmidt benh@kernel.crashing.org CC: Paul Mackerras paulus@samba.org CC: Grant Likely grant.likely@secretlab.ca CC: Rob Herring rob.herring@calxeda.com CC: linuxppc-dev@lists.ozlabs.org CC: devicetree-discuss@lists.ozlabs.org CC: Richard Henderson rth@twiddle.net CC: Ivan Kokshaysky ink@jurassic.park.msu.ru CC: Matt Turner mattst88@gmail.com CC: linux-alpha@vger.kernel.org CC: Thomas Gleixner tglx@linutronix.de CC: Ingo Molnar mingo@redhat.com CC: "H. Peter Anvin" hpa@zytor.com CC: x86@kernel.org CC: Tony Luck tony.luck@intel.com CC: Fenghua Yu fenghua.yu@intel.com CC: linux-ia64@vger.kernel.org CC: Will Deacon will.deacon@arm.com CC: Peter Zijlstra a.p.zijlstra@chello.nl CC: Arnaldo Carvalho de Melo acme@ghostprotocols.net CC: Russell King linux@arm.linux.org.uk CC: linux-arm-kernel@lists.infradead.org
Gilad Ben-Yossef (9): arm: avoid using on_each_cpu hard coded ret value ia64: avoid using on_each_cpu hard coded ret value x86: avoid using on_each_cpu hard coded ret value alpha: avoid using on_each_cpu hard coded ret value ppc: avoid using on_each_cpu hard coded ret value agp: avoid using on_each_cpu hard coded ret value drm: avoid using on_each_cpu hard coded ret value smp: refactor on_each_cpu to void returning func x86: refactor wbinvd_on_all_cpus to void function
arch/alpha/kernel/smp.c | 7 ++----- arch/arm/kernel/perf_event.c | 2 +- arch/ia64/kernel/perfmon.c | 12 ++---------- arch/powerpc/kernel/rtas.c | 3 +-- arch/x86/include/asm/smp.h | 5 ++--- arch/x86/lib/cache-smp.c | 4 ++-- drivers/char/agp/generic.c | 3 +-- drivers/gpu/drm/drm_cache.c | 3 +-- include/linux/smp.h | 7 +++---- kernel/smp.c | 6 ++---- 10 files changed, 17 insertions(+), 35 deletions(-)