Date: Tue, 28 Dec 2004 16:53:49 -0500 (EST) From: "Andrew R. Reiter" <arr@watson.org> To: John Baldwin <jhb@FreeBSD.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern subr_witness.c Message-ID: <20041228165334.G36918@fledge.watson.org> In-Reply-To: <200412281048.42213.jhb@FreeBSD.org> References: <200412262252.iBQMqPe7060613@repoman.freebsd.org> <20041227172424.A85914@fledge.watson.org> <200412281048.42213.jhb@FreeBSD.org>
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On Tue, 28 Dec 2004, John Baldwin wrote:
:On Monday 27 December 2004 05:27 pm, Andrew R. Reiter wrote:
:> On Mon, 27 Dec 2004, John Baldwin wrote:
:> :On Sunday 26 December 2004 07:54 pm, Kris Kennaway wrote:
:> :> On Sun, Dec 26, 2004 at 10:52:24PM +0000, Robert Watson wrote:
:> :> > rwatson 2004-12-26 22:52:24 UTC
:> :> >
:> :> > FreeBSD src repository
:> :> >
:> :> > Modified files:
:> :> > sys/kern subr_witness.c
:> :> > Log:
:> :> > Add "show alllocks" command to DDB, which dumps a list of processes
:> :> > and threads currently holding sleep mutexes (and spin mutexes for
:> :> > curthread). This can be quite useful in looking for a lock
:> :> > condition summary for a system, as it avoids manually iterating
:> :> > through threads and processes to find all the interesting locks.
:> :> >
:> :> > NB: "alllocks" is up there with "lockedvnods" for a bad argument for
:> :> > show.
:> :>
:> :> ITYM "allloks" or perhaps "alllockes" (conservation of vowels).
:> :
:> :If you want a better name you could do 'show locks /a' instead. That is,
:> : add support to 'show locks' for the /a option (see 'show ktr' for how you
:> : would handle this by looking at 'modif').
:>
:> Seems like a good idea to me, John. My only -- very minor -- issue with
:> that is using '/' as the flag delimiter. Not trying to be an asshole or
:> anything, just seems to me that (unless there is some ddb options already
:> there that use '/') using the forward slash is very cmd.exe-esque.
:>
:> I agree, however, that having show locks <flag-option> is a good idea
:> instead of two different commands.
:
:The / is part of ddb itself. Each ddb command (except those that do their own
:command line parsing) is called with a variable containing the arguments and
:another variable (modif) containing a string of any options specified via /.
:For example:
:
:DB_SHOW_COMMAND(ktr, db_ktr_all)
:{
: int quit;
:
: quit = 0;
: tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
: tstate.first = -1;
: if (strcmp(modif, "v") == 0)
: db_ktr_verbose = 1;
: else
: db_ktr_verbose = 0;
: if (strcmp(modif, "a") == 0) {
: while (cncheckc() != -1)
: if (db_mach_vtrace() == 0)
: break;
: } else {
: db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
: while (!quit)
: if (db_mach_vtrace() == 0)
: break;
: }
:}
:
:This implements 'show ktr' and allows 'show ktr /a' and 'show ktr /v'. Note
:that it doesn't handle 'show ktr /av' or 'show ktr /va'. :-)
:
Oh. :-)
--
Andrew R. Reiter
arr@watson.org
arr@FreeBSD.org
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