linux/tools/perf/bench/mem-memcpy-x86-64-asm.S

#define memcpy MEMCPY /* don't hide glibc's memcpy() */
#define altinstr_replacement text
#define globl p2align 4; .globl
#include "../../../arch/x86/lib/memcpy_64.S"
/*
 * We need to provide note.GNU-stack section, saying that we want
 * NOT executable stack. Otherwise the final linking will assume that
 * the ELF stack should not be restricted at all and set it RWX.
 */
.section .note.GNU-stack,"",@progbits
perf bench: Make "default" memcpy() selection actually use glibc's implementation Since arch/x86/lib/memcpy_64.S implements not only __memcpy, but also memcpy, without further precautions this function will get chose by the static linker for resolving all references, and hence the "default" measurement didn't really measure anything else than the "x86-64-unrolled" one. Fix this by renaming (through the pre-processor) the conflicting symbol. On my Westmere system, the glibc variant turns out to require about 4% less instructions, but 15% more cycles for the default 1Mb block size measured. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F16D6FD020000780006D72F@nat28.tlf.novell.com Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 2012-01-18 13:28:13 +00:00			`#define memcpy MEMCPY /* don't hide glibc's memcpy() */`
perf bench: Also allow measuring alternative memcpy implementations Intended to be able to support the current selection of the preferred memcpy() implementation, this patch adds the ability to also measure the two alternative implementations, again by way of using some pre-processsor replacement. While on my Westmere system this proves that the movsb based variant is worse than the movsq based one (since the ERMS feature isn't there), it also shows that here for the default as well as small sizes the unrolled variant outperforms the movsq one. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/4F16D728020000780006D732@nat28.tlf.novell.com Signed-off-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 2012-01-18 13:28:56 +00:00			`#define altinstr_replacement text`
			`#define globl p2align 4; .globl`
perf bench: Add feature that measures the performance of the arch/x86/lib/memcpy_64.S memcpy routines via 'perf bench mem' This patch ports arch/x86/lib/memcpy_64.S to perf bench mem memcpy for benchmarking memcpy() in userland with tricky and dirty way. util/include/asm/cpufeature.h, util/include/asm/dwarf2.h, and util/include/linux/linkage.h are mostly dummy files with small wrappers, so that we are able to include memcpy_64.S unmodified. Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp> Cc: h.mitake@gmail.com Cc: Miao Xie <miaox@cn.fujitsu.com> Cc: Ma Ling <ling.ma@intel.com> Cc: Zhao Yakui <yakui.zhao@intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andi Kleen <andi@firstfloor.org> LKML-Reference: <1290668693-27068-2-git-send-email-mitake@dcl.info.waseda.ac.jp> Signed-off-by: Ingo Molnar <mingo@elte.hu> 2010-11-25 16:04:53 +09:00			`#include "../../../arch/x86/lib/memcpy_64.S"`
perf tools: Fix perf stack to non executable on x86_64 By adding following objects: bench/mem-memcpy-x86-64-asm.o the x86_64 perf binary ended up with executable stack. The reason was that above object are assembler sourced and is missing the GNU-stack note section. In such case the linker assumes that the final binary should not be restricted at all and mark the stack as RWX. Adding section ".note.GNU-stack" definition to mentioned object, with all flags disabled, thus omiting this object from linker stack flags decision. Problem introduced in: $ git describe ea7872b v2.6.37-rc2-19-gea7872b Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=783570 Reported-by: Clark Williams <williams@redhat.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1328100848-5630-1-git-send-email-jolsa@redhat.com Signed-off-by: Jiri Olsa <jolsa@redhat.com> [ committer note: Backported fix to perf/urgent (3.3-rc2+) ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> 2012-02-06 18:54:06 -02:00			`/*`
			`* We need to provide note.GNU-stack section, saying that we want`
			`* NOT executable stack. Otherwise the final linking will assume that`
			`* the ELF stack should not be restricted at all and set it RWX.`
			`*/`
			`.section .note.GNU-stack,"",@progbits`