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! The only change from the first version is the addition of a proper Signed-off-by line. This patch set is also available on branch on_each_cpu_ret_v2 at git://github.com/gby/linux.git Signed-off-by: Gilad Ben-Yossef <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Reviewed-by: Michal Nazarewicz <[email protected]> CC: Michal Nazarewicz <[email protected]> CC: David Airlie <[email protected]> CC: [email protected] CC: Benjamin Herrenschmidt <[email protected]> CC: Paul Mackerras <[email protected]> CC: Grant Likely <[email protected]> CC: Rob Herring <[email protected]> CC: [email protected] CC: [email protected] CC: Richard Henderson <[email protected]> CC: Ivan Kokshaysky <[email protected]> CC: Matt Turner <[email protected]> CC: [email protected] CC: Thomas Gleixner <[email protected]> CC: Ingo Molnar <[email protected]> CC: "H. Peter Anvin" <[email protected]> CC: [email protected] CC: Tony Luck <[email protected]> CC: Fenghua Yu <[email protected]> CC: [email protected] CC: Will Deacon <[email protected]> CC: Peter Zijlstra <[email protected]> CC: Arnaldo Carvalho de Melo <[email protected]> CC: Russell King <[email protected]> CC: [email protected] 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(-) _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
