From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: trace_printk() support in trace-cmd Date: Mon, 15 Nov 2010 19:31:16 +0200 Message-ID: <4CE16E64.2040909@redhat.com> References: <4CE16941.3080008@redhat.com> <1289841107.12418.602.camel@gandalf.stny.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-trace-users@vger.kernel.org, KVM list To: Steven Rostedt Return-path: In-Reply-To: <1289841107.12418.602.camel@gandalf.stny.rr.com> Sender: linux-trace-users-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 11/15/2010 07:11 PM, Steven Rostedt wrote: > On Mon, 2010-11-15 at 19:09 +0200, Avi Kivity wrote: > > trace-cmd doesn't like trace_printk(): > > > > <...>-23775 [000] 26343.288803: kvm_emulate_insn: 0:f14e9: rep insb > > <...>-23775 [000] 26343.288804: bprint: x86_emulate_insn : > > (NO FORMAT FOUND at ffffffffa0131460) > > > > <...>-23775 [000] 26343.288807: bprint: x86_emulate_insn : > > (NO FORMAT FOUND at ffffffffa0131460) > > > > any chance to get it to work with custom printks? > > > > I guess I should use 'perf probe' instead. > > > > Which kernel are you using, and/or which trace-cmd? It works fine for > me. But there has been bugs with older kernels and older trace-cmds. kernel 2.6.37-rc1+, I think latest trace-cmd; will retry. Meanwhile 'perf probe' grumbles on anonymous unions: > src(tyep:operand) has no member val. > Failed to find 'ctxt' in this function. > Error: Failed to add events. (-22) For --add 'insb=arch/x86/kvm/emulate.c:3369 insn=ctxt->decode.b bytes=ctxt->decode.dst.bytes port=ctxt->decode.src.val cx=ctxt->decode.regs[1] di=ctxt->decode.regs[7] addr=ctxt->decode.dst.mem.addr cpos=ctxt->decode.io_read.pos cend=ctxt->decode.io_read.end' (ctxt->decode.src.val is a member of an anonymous union in ctxt->decode.src, which is of type 'struct operand') -- error compiling committee.c: too many arguments to function