From: Steven Rostedt <rostedt@goodmis.org>
To: Phil Auld <pauld@redhat.com>
Cc: Slavomir Kaslev <kaslevs@vmware.com>,
linux-trace-devel@vger.kernel.org, ykaradzhov@vmware.com,
jbacik@fb.com, tstoyanov@vmware.com, slavomir.kaslev@gmail.com
Subject: Re: [PATCH v4 1/2] trace-cmd: Optimize how pid filters are expressed
Date: Wed, 17 Apr 2019 10:54:23 -0400 [thread overview]
Message-ID: <20190417105423.1cf2caad@gandalf.local.home> (raw)
In-Reply-To: <20190417135858.GD6118@pauld.bos.csb>
On Wed, 17 Apr 2019 09:58:58 -0400
Phil Auld <pauld@redhat.com> wrote:
> FILTER write /sys/kernel/debug/tracing/events/sched/sched_switch/filter (len 142) value "(common_pid<21420||common_pid>21425)&&(common_pid<21265||common_pid>21418)||(next_pid<21420||next_pid>21425)&&(next_pid<21265||next_pid>21418)"
>
>
> The latter is correct given precendce of && before || but I wonder if () don't make sense? I always have to look
> that one up :)
Yes, as the one who wrote the parsing code (and was lectured by
Al Viro about it), I know for a fact that && has a higher precedence
than the || and it should work. I was about to comment about that, but
then remembered my "lesson" :-)
-- Steve
>
> If I were writing that in code I'd probably put in the extra ()s, but since it's generated and no
> one actually sees it, probably okay and simpler as is.
next prev parent reply other threads:[~2019-04-17 14:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-17 13:09 [PATCH v4 0/2] Optimize pid filters Slavomir Kaslev
2019-04-17 13:09 ` [PATCH v4 1/2] trace-cmd: Optimize how pid filters are expressed Slavomir Kaslev
2019-04-17 13:58 ` Phil Auld
2019-04-17 14:18 ` John Kacur
2019-04-17 14:25 ` Phil Auld
2019-04-17 14:52 ` Steven Rostedt
2019-04-17 14:52 ` Steven Rostedt
2019-04-17 14:54 ` Steven Rostedt [this message]
2019-04-17 13:09 ` [PATCH v4 2/2] trace-cmd: Document record --no-filter option in record's man page Slavomir Kaslev
2019-04-17 14:05 ` Phil Auld
2019-04-17 16:19 ` Steven Rostedt
2019-04-17 16:24 ` Steven Rostedt
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