[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20130408105253.GA5275@redhat.com>
Date: Mon, 8 Apr 2013 06:52:53 -0400
From: "Frank Ch. Eigler" <fche@...hat.com>
To: Mel Gorman <mgorman@...e.de>
Cc: "Theodore Ts'o" <tytso@....edu>, linux-ext4@...r.kernel.org,
LKML <linux-kernel@...r.kernel.org>,
Linux-MM <linux-mm@...ck.org>, Jiri Slaby <jslaby@...e.cz>
Subject: Re: Excessive stall times on ext4 in 3.9-rc2
Hi, Mel -
> > [...] git kernel developers
> > should use git systemtap, as has always been the case. [...]
>
> At one point in the past this used to be the case but then systemtap had to
> be compiled as part of automated tests across different kernel versions. It
> could have been worked around in various ways or even installed manually
> when machines were deployed but stap-fix.sh generally took less time to
> keep working.
OK, if that works for you. Keep in mind though that newer versions of
systemtap retain backward-compatibility for ancient versions of the
kernel, so git systemtap should work on those older versions just
fine.
> [...]
> Yes, this was indeed the problem. The next version of watch-dstate.pl
> treated get_request_wait() as a function that may or may not exist. It
> uses /proc/kallsyms to figure it out.
... or you can use the "?" punctuation in the script to have
systemtap adapt:
probe kprobe.function("get_request_wait") ? { ... }
- FChE
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists