From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: Re: [PATCH] perf symbol: Fix kernel symbol address display Date: Fri, 24 Apr 2020 12:06:31 -0300 Message-ID: <20200424150631.GN19437@kernel.org> References: <20200415070744.59919-1-tmricht@linux.ibm.com> <20200420204617.GA23638@kernel.org> <475a5c86-2be3-4f12-56f3-7bd6587e8ec3@linux.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <475a5c86-2be3-4f12-56f3-7bd6587e8ec3@linux.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: Thomas Richter Cc: Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, gor@linux.ibm.com, sumanthk@linux.ibm.com, heiko.carstens@de.ibm.com List-Id: linux-perf-users.vger.kernel.org Em Fri, Apr 24, 2020 at 02:37:01PM +0200, Thomas Richter escreveu: > On 4/20/20 10:46 PM, Arnaldo Carvalho de Melo wrote: > > Em Wed, Apr 15, 2020 at 09:07:44AM +0200, Thomas Richter escreveu: > >> Running commands > >> > >> ./perf record -e rb0000 -- find . > >> ./perf report -v > > > > Or when pressing 'V' in the TUI. > > > >> reveals symbol names and its addresses. There is a mismatch between > > > > Yeah, an address that at some point was put there to help with debugging > > the symbol resolution, IIRC how it looked like when looking at > > > > readelf -sW vmlinux > > > > Or any other DSO, for instance, for a glibc symbol here: > > > > Using 'perf report -s pid,dso,sym' then pressing 'V': > > > > 1.55% 20325:perf /usr/lib64/libc-2.30.so 0x161825 B [.] __strlen_avx2 > > > > [acme@five perf]$ readelf -sW /usr/lib64/libc-2.30.so | grep strlen_avx2 > > 24371: 0000000000161810 414 FUNC LOCAL DEFAULT 15 __strlen_avx2 > > [acme@five perf]$ > > > > Can you check if doing in /lib/modules/.../build/vmlinux produces what > > appears when 'V' is in place? > > > > And perhaps we can also show the DSO offset and the rip as it gets laid > > out in memory in the end? So we have all the informations? > > > > - Arnaldo > > > > Arnaldo, > > having verified this also works in the TUI mode using 'V', are you going to pick > this patch? That would be a change in behaviour, the original intent was to show the value one would get from the ELF symbol table, isn't that the case? That is why I asked if you would think that providing the information you want, which is matching to what is in kallsyms, would be interesting, which I think it is, but how? showing the vmlinux offset somehow? > Thanks > > > -- > Thomas Richter, Dept 3252, IBM s390 Linux Development, Boeblingen, Germany > -- > Vorsitzender des Aufsichtsrats: Matthias Hartmann > Geschäftsführung: Dirk Wittkopp > Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294 -- - Arnaldo