Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819AbcD2Cd3 (ORCPT ); Thu, 28 Apr 2016 22:33:29 -0400 Received: from mail-pa0-f68.google.com ([209.85.220.68]:35640 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752455AbcD2Cd2 (ORCPT ); Thu, 28 Apr 2016 22:33:28 -0400 Date: Fri, 29 Apr 2016 20:33:19 +0900 From: Namhyung Kim To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Hemant Kumar , Ananth N Mavinakayanahalli Subject: Re: [PATCH perf/core v5 05/15] perf probe: Use cache entry if possible Message-ID: <20160429113319.GA3094@danjae.aot.lge.com> References: <20160427183701.23446.15293.stgit@devbox> <20160427183752.23446.10615.stgit@devbox> <20160428024753.GB15597@sejong.aot.lge.com> <20160429085229.8d605ba101838f6552195a53@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160429085229.8d605ba101838f6552195a53@kernel.org> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3082 Lines: 99 Hi Masami, On Fri, Apr 29, 2016 at 08:52:29AM +0900, Masami Hiramatsu wrote: > On Thu, 28 Apr 2016 11:47:53 +0900 > Namhyung Kim wrote: > > > On Thu, Apr 28, 2016 at 03:37:52AM +0900, Masami Hiramatsu wrote: > > > From: Masami Hiramatsu > > > > > > Before analyzing debuginfo, try to find a corresponding entry > > > from probe cache always. This does not depend on --cache, > > > the --cache enables to store/update cache, but looking up > > > the cache is always enabled. > > > > > > Signed-off-by: Masami Hiramatsu > > > Signed-off-by: Masami Hiramatsu > > > --- > > > > [SNIP] > > > +static int find_probe_trace_events_from_cache(struct perf_probe_event *pev, > > > + struct probe_trace_event **tevs) > > > +{ > > > + struct probe_cache *cache; > > > + struct probe_cache_entry *entry; > > > + struct probe_trace_event *tev; > > > + struct str_node *node; > > > + int ret, i; > > > + > > > + cache = probe_cache__new(pev->target); > > > + if (!cache) > > > + return 0; > > > + > > > + entry = probe_cache__find(cache, pev); > > > + > > > + if (!entry && !pev->event && > > > + (!pev->point.file && pev->point.function && !pev->point.retprobe && > > > + !pev->point.line && !pev->point.offset && !pev->point.lazy_line)) { > > > + entry = probe_cache__find_by_name(cache, pev->group, > > > + pev->point.function); > > > + } > > > > What about arguments? It seems that it only checks group and event > > names of the given pev and use the cached entry's tev if found. What > > if they have different argument spec? > > Indeed. I think this is for reusing cached event by using event name. > however, with 11/15 ("perf probe: Accept %sdt and %cached event name"), > we don't need this anymore. > > So, I'll remove this fallback code. Let's think about the following case: if user added an event to cache with argument XXX earlier and she tries to add the same event but with different argument YYY later. But the event is in the cache so it'll reuse the cached event with XXX, no? Thanks, Namhyung > > > > > > > + if (!entry) { > > > + ret = 0; > > > + goto out; > > > + } > > > + > > > + ret = strlist__nr_entries(entry->tevlist); > > > + if (ret > probe_conf.max_probes) { > > > + pr_debug("Too many entries matched in the cache of %s\n", > > > + pev->target ? : "kernel"); > > > + ret = -E2BIG; > > > + goto out; > > > + } > > > + > > > + *tevs = zalloc(ret * sizeof(*tev)); > > > + if (!*tevs) { > > > + ret = -ENOMEM; > > > + goto out; > > > + } > > > + > > > + i = 0; > > > + strlist__for_each(node, entry->tevlist) { > > > + tev = &(*tevs)[i++]; > > > + ret = parse_probe_trace_command(node->s, tev); > > > + if (ret < 0) > > > + goto out; > > > + /* Set the uprobes attribute as same as original */ > > > + tev->uprobes = pev->uprobes; > > > + } > > > + ret = i; > > > + > > > +out: > > > + probe_cache__delete(cache); > > > + return ret; > > > +} > > > -- > Masami Hiramatsu