Heiko Carstens wrote: > On Wed, Apr 14, 2010 at 07:46:12AM -0700, Masami Hiramatsu wrote: >> Ian Munsie wrote: >>> From: Ian Munsie <imun...@au.ibm.com> >>> >>> The perf userspace tool included some architecture specific code to map >>> registers from the DWARF register number into the names used by the regs >>> and stack access API. >>> >>> This patch moves the architecture specific code out into a separate >>> arch/x86 directory along with the infrastructure required to use it. >>> >>> Signed-off-by: Ian Munsie <imun...@au.ibm.com> >>> --- >>> Changes since v1: From Masami Hiramatsu's suggestion, I added a check in the >>> Makefile for if the arch specific Makefile defines PERF_HAVE_DWARF_REGS, >>> printing a message during build if it has not. This simplifies the code >>> removing the odd macro from the previous version and the need for an arch >>> specific arch_dwarf-regs.h. I have not entirely disabled DWARF support for >>> architectures that don't implement the register mappings, so that they can >>> still add a probe based on a line number (they will be missing the ability >>> to >>> capture the value of a variable from a register). >> >> Hmm, sorry, I don't think it is a good way to go... IMHO, porting >> dwarf-regs.c >> is so easy (you can just refer systemtap/runtime/loc2c-runtime.h), easier >> than porting kprobe-tracer on another arch. And perf is a part of kernel >> tree. >> It means that someone who are porting kprobe-tracer, he should port >> dwarf-regs.c too. In that case, PERF_HAVE_DWARF_REGS flag will be used only >> between those two patches in same patchset. So, I suggested you to drop dwarf >> support if dwarf-regs mapping doesn't exist. >> >> AFAIK, at this point, only s390 users are affected. I'd like to ask >> them to just port a register mapping on perf and test it too. > > Hm, I'm a bit lost here. Probably due to lack of context. What would be > missing > on s390 and what am I supposed to implement and how can I test it? > Any pointers to git commits?
Ah, sorry about that. Now we're talking about an idea about porting perf-probe on some architectures which supports kprobe-tracer. Ian's patch (https://patchwork.kernel.org/patch/92328/) is currently under discussion, so there is no git commit yet (but it will be in a few days). So what I'd like to suggest you is implementing s390 version of DWARF register mapping support(ppc version is here: https://patchwork.kernel.org/patch/92329/) for perf probe (a subcommand of perf tools(tools/perf)) and test the perf-probe can work. For testing, you may need to compile kernel with CONFIG_DEBUG_INFO, install elfutils-devel, and make perf tools (cd tools/perf; make). And then, execute below command. $ ./perf probe -v --add 'vfs_read file' Thank you, -- Masami Hiramatsu e-mail: mhira...@redhat.com _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
