Messages in this thread |  | | Date | Mon, 13 Apr 2015 23:38:19 +0800 | From | He Kuang <> | Subject | Re: [PATCH 1/3] perf probe: Set retprobe flag when probe in address-based alternative mode |
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Hi, Arnaldo
On 04/13/2015 10:42 PM, Arnaldo Carvalho de Melo wrote: > Em Mon, Apr 13, 2015 at 11:39:03AM -0300, Arnaldo Carvalho de Melo escreveu: >> Em Mon, Apr 13, 2015 at 07:41:28PM +0800, He Kuang escreveu: >>> Perf probe misses to set retprobe flag back when falling back to >>> address-based alternative mode. > >> Humm, noticed one other problem, but not with your patch, about this message: > >> "Could not open debuginfo. Try to use symbols." > >> That is really not clear, specially that "try to use symbols" :-) > >> [root@ssdandy ~]# ls -la /root/.debug/.build-id/dd/32e51921ede0fd46f034091b7f6a0f2e01ebda >> lrwxrwxrwx. 1 root root 86 Apr 10 18:02 /root/.debug/.build-id/dd/32e51921ede0fd46f034091b7f6a0f2e01ebda -> ../../home/acme/git/build/v4.0.0-rc6+/vmlinux/dd32e51921ede0fd46f034091b7f6a0f2e01ebda >> [root@ssdandy ~]# ls -la /root/.debug/.build-id/dd/../../home/acme/git/build/v4.0.0-rc6+/vmlinux/dd32e51921ede0fd46f034091b7f6a0f2e01ebda >> -rwxr-xr-x. 1 root root 22698661 Apr 10 18:02 /root/.debug/.build-id/dd/../../home/acme/git/build/v4.0.0-rc6+/vmlinux/dd32e51921ede0fd46f034091b7f6a0f2e01ebda >> [root@ssdandy ~]# ls -la /root/.debug/.build-id/dd/../../home/acme/git/build/v4.0.0-rc6+/vmlinux/dd32e51921ede0fd46f034091b7f6a0f2e01ebda > >> I.e. it managed to read the debuginfo, its just that it has no symbols in it :-) > >> Anyway, digression ended. > > Interesting is that when testing your next patch I see: > > [root@ssdandy linux]# perf probe -s ./kernel_src/ --add='fs/super.c;s->s_count=1;' > The /root/.debug/.build-id/dd/32e51921ede0fd46f034091b7f6a0f2e01ebda file has no debug information. > Rebuild with CONFIG_DEBUG_INFO=y, or install an appropriate debuginfo package. > Error: Failed to add events. > [root@ssdandy linux]# > > Much, much clear message about that debuginfo file :-) > > But then, to test your [2/3] patch I'll have to figure out how to setup the > environment so that I can match your results, shouldn't be hard, but would > save reviewing time if you stated it in the commit log message.
Sorry for not providing enough information.
-s ./kernel_src/
The kernel_src dir is a kernel source tree path, it can be anywhere, for test you can only put fs/super.c in it:
kernel_src/ -- fs -- super.c
-k vmlinux
This is necessary and should be matched to your running kernel.
> > - Arnaldo > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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