From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: Date: Mon, 9 Nov 2009 23:05:56 -0500 Message-ID: <9ab217670911092005q6e6327c7yb99b6910408973eb@mail.gmail.com> From: "Devon H. O'Dell" To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [9fans] dtrace for plan 9 Topicbox-Message-UUID: 987d520a-ead5-11e9-9d60-3106f5b1d025 2009/11/9 erik quanstrom : >> DTrace by itself is pretty lame. It needs providers to be interesting. >> By itself, it's a very limited interpreter that supports BEGIN and >> END, and a couple other tiny things (ERROR, maybe?). Devtrace would be >> analogous to the syscall provider for DTrace, from my understanding. > > i may be misunderstanding you, but devtrace can trace any > call site or return in the kernel. =A0not just system calls. and > not just entire functions; one could enable tracing on just > one return, for example. > > you just give it a range of addresses and it loops through finding > the magic left by the linker. =A0enabling a trace atomicly modifies > each site to turn on tracing. Ok, I didn't realize the scope. >> I'd estimate a finished version to be about the size of >> the Plan 9 kernel. > > minooka; wc -l /sys/src/9/*/*trace*.[chs] /sys/src/libc/386/trace.s > =A0 =A0118 /sys/src/9/pc/archtrace.c > =A0 =A0 18 /sys/src/9/pc/archtrace.h > =A0 =A0578 /sys/src/9/port/devtrace.c > =A0 =A0 33 /sys/src/libc/386/trace.s > =A0 =A0747 total > > this stuff's ready to take off. =A0(har har har.) Sure, but it's still not the entire functionality :) --dho > - erik > >