Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759319Ab0D3SuK (ORCPT ); Fri, 30 Apr 2010 14:50:10 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:46457 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758774Ab0D3Sti (ORCPT ); Fri, 30 Apr 2010 14:49:38 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=ByGsjyZPx0cKwP/jUN4N+HX0LyImdIpxVmZesHqRaTVqZ9WblBqz7mZ4fjtkKnJynI aGPd4LNTXBkyYw3kOQW6Apei3YZx8ToF2YgbCyUTCKZtmGKbfRhtP193YJ1Rbld7sOWC /ra6DsGWQRFHY0S31ykknon8kY9LgpX37Xr+o= Date: Fri, 30 Apr 2010 20:49:39 +0200 From: Frederic Weisbecker To: Hitoshi Mitake Cc: linux-kernel@vger.kernel.org, h.mitake@gmail.com, Ingo Molnar , Peter Zijlstra , Paul Mackerras , Arnaldo Carvalho de Melo , Jens Axboe , Jason Baron , Xiao Guangrong Subject: Re: [PATCH v2] perf lock: add "info" subcommand for dumping misc information Message-ID: <20100430184937.GB5357@nowhere> References: <1272074742-3654-2-git-send-regression-fweisbec@gmail.com> <1272106001-10519-1-git-send-email-mitake@dcl.info.waseda.ac.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1272106001-10519-1-git-send-email-mitake@dcl.info.waseda.ac.jp> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4571 Lines: 176 On Sat, Apr 24, 2010 at 07:46:41PM +0900, Hitoshi Mitake wrote: > Hi Frederic, > > I added "info" subcommand to perf lock, > this can be used as dumping metadata like thread or address of lock instances. > "map" was removed because info should do the work of it. > > This will be useful not only for debugging but also for ordinary analyzing. > > I made this patch on perf/core of your tree, could you queue this? > > v2: adding example of usage > % sudo ./perf lock info -t > | Thread ID: comm > | 0: swapper > | 1: init > | 18: migration/5 > | 29: events/2 > | 32: events/5 > | 33: events/6 > ... > > % sudo ./perf lock info -m > | Address of instance: name of class > | 0xffff8800b95adae0: &(&sighand->siglock)->rlock > | 0xffff8800bbb41ae0: &(&sighand->siglock)->rlock > | 0xffff8800bf165ae0: &(&sighand->siglock)->rlock > | 0xffff8800b9576a98: &p->cred_guard_mutex > | 0xffff8800bb890a08: &(&p->alloc_lock)->rlock > | 0xffff8800b9522a08: &(&p->alloc_lock)->rlock > | 0xffff8800bb8aaa08: &(&p->alloc_lock)->rlock > | 0xffff8800bba72a08: &(&p->alloc_lock)->rlock > | 0xffff8800bf18ea08: &(&p->alloc_lock)->rlock > | 0xffff8800b8a0d8a0: &(&ip->i_lock)->mr_lock > | 0xffff88009bf818a0: &(&ip->i_lock)->mr_lock > | 0xffff88004c66b8a0: &(&ip->i_lock)->mr_lock > | 0xffff8800bb6478a0: &(shost->host_lock)->rlock > Signed-off-by: Hitoshi Mitake > Cc: Ingo Molnar > Cc: Peter Zijlstra > Cc: Paul Mackerras > Cc: Arnaldo Carvalho de Melo > Cc: Jens Axboe > Cc: Jason Baron > Cc: Xiao Guangrong I've eventually not queued it because of some various problems, see below: > --- > tools/perf/builtin-lock.c | 68 +++++++++++++++++++++++++++++++++++++++++++-- > 1 files changed, 65 insertions(+), 3 deletions(-) > > diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c > index ce27675..c54211e 100644 > --- a/tools/perf/builtin-lock.c > +++ b/tools/perf/builtin-lock.c > @@ -778,18 +778,61 @@ static void print_result(void) > } > } > > +static int info_threads; > +static int info_map; > + > +static void rec_dump_threads(struct rb_node *node) > +{ > + struct thread_stat *st; > + struct thread *t; > + > + if (!node) > + return; > + > + if (node->rb_left) > + rec_dump_threads(node->rb_left); That only walks the left nodes of the rbtree, imagine the following rbtree, W are visited nodes, U are the unvisited: Root / \ W U / \ / \ W U U U Better iterate using rb_first() then rb_next() until it is NULL. > + > + st = container_of(node, struct thread_stat, rb); > + BUG_ON(!st); You won't ever have !st because container_of computes an address based on a struct type and a contained address inside this struct. struct thread_stat { struct list_head hash_entry; struct rb_node rb; [...] } ts; If ts->rb == 1000, ts == 1000 - 16 or something like this. What matters is the "if (!node)" check you did before. > + t = perf_session__findnew(session, st->tid); > + BUG_ON(!t); > + > + printf("%10d: %s\n", st->tid, t->comm); Please don't use printf anymore (I did the same mistakes lately), now that are using a TUI and we might use a GUI one day, we can't assume anymore we are dealing with a normal stdout. So better use pr_debug, pr_err, pr_warning, etc... > + > + if (node->rb_right) > + rec_dump_threads(node->rb_right); > +} > + > +static void dump_threads(void) > +{ > + printf("%10s: comm\n", "Thread ID"); Same here and below. > + rec_dump_threads(thread_stats.rb_node); > +} > + > static void dump_map(void) > { > unsigned int i; > struct lock_stat *st; > > + printf("Address of instance: name of class\n"); > for (i = 0; i < LOCKHASH_SIZE; i++) { > list_for_each_entry(st, &lockhash_table[i], hash_entry) { > - printf("%p: %s\n", st->addr, st->name); > + printf(" %p: %s\n", st->addr, st->name); > } > } > } > > +static void dump_info(void) > +{ > + /* ugly... */ > + if (info_threads) > + dump_threads(); No it's not ugly, it's ok, we do this everywhere in perf tools :) Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/