From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Melo Subject: Re: [PATCH] perf tools: update docs regarding kernel/user space unwinding Date: Fri, 27 Mar 2020 17:17:59 -0300 Message-ID: References: <20200325164053.10177-1-tonyj@suse.de> <38ba2caa-dadd-52c4-c6ea-5e01b7e59ee2@us.ibm.com> <20200327200934.GB2715@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20200327200934.GB2715@suse.de> Sender: linux-kernel-owner@vger.kernel.org To: Tony Jones Cc: linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org List-Id: linux-perf-users.vger.kernel.org On March 27, 2020 5:09:34 PM GMT-03:00, Tony Jones wrote= : >On Thu, Mar 26, 2020 at 04:32:26PM -0500, Paul Clarke wrote: >> > + and 'lbr'=2E The value 'dwarf' is effective only if libunwind >> > + (or a recent version of libdw) is present on the system; >> > + the value 'lbr' only works for certain cpus=2E The method for >> > + kernel space is controlled not by this option but by the >> > + kernel config (CONFIG_UNWINDER_*)=2E >>=20 >> Your changes are just copying the old text, so this isn't a criticism >of your patches=2E >>=20 >> Do we have information to replace "a recent version of libdw", which >will quickly get stale? > >Hi Paul=2E > >The original "(libunwind or a recent version of libdw)" text was from >Feb 2016=2E So a while ago=2E Unfortunate wording, would be better to have the version where the require= d feature was added to libdw=2E > >bd0419e2a5a9f requires >=3D 0=2E157 but this is for probing=2E 0a4f2b6a3= ba50 >specifies >=3D 0=2E158 but I see no mention of=20 >why in the commit but since it's from 2014 and elfutils is now at >0=2E178, I think it's safe to just remove the=20 >reference=2E > >As an aside, there is a lot of detail in perf-config=2Etxt that's >available in some of the other subcomands help files=2E >Seems a good way for things to get stale=2E It could also do with some >grammatical cleanup=2E English as a second language, many contributors, please consider sending f= ixes, would be really appreciated, Thanks, - Arnaldo > >Tony --=20 Sent from my Android device with K-9 Mail=2E Please excuse my brevity=2E