From: David Ahern <dsahern@gmail.com>
To: Andrew Jones <drjones@redhat.com>, acme@ghostprotocols.net
Cc: linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl,
paulus@samba.org, mingo@redhat.com, tzanussi@gmail.com
Subject: Re: perf script: rwtop: SIGALRM and pipe read race
Date: Mon, 17 Sep 2012 09:16:19 -0600 [thread overview]
Message-ID: <50573EC3.6020209@gmail.com> (raw)
In-Reply-To: <505739EF.5010000@gmail.com>
On 9/17/12 8:55 AM, David Ahern wrote:
> 2. the rwtop.pl script is not handling negative return values ($ret < 0)
> properly -- the '$ret > 0' check is succeeding even though $ret is
> negative (e.g., -EAGAIN) leading to astronomical read values
I think perl is treating $ret as an unsigned integer.
Again, I know little about perl, but this change to
./scripts/perl/rwtop.pl makes it behave properly:
my $n = sprintf("%d", $ret);
if ($n > 0) {
...
David
next prev parent reply other threads:[~2012-09-17 15:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-14 15:39 perf script: rwtop: SIGALRM and pipe read race Andrew Jones
2012-09-14 16:05 ` David Ahern
2012-09-14 18:10 ` Andrew Jones
2012-09-17 14:55 ` David Ahern
2012-09-17 15:16 ` David Ahern [this message]
2012-09-17 16:02 ` Arnaldo Carvalho de Melo
2012-09-17 16:32 ` David Ahern
2012-09-17 17:12 ` Arnaldo Carvalho de Melo
2012-09-17 20:10 ` David Ahern
2012-09-18 9:05 ` Andrew Jones
2012-09-18 9:30 ` Andrew Jones
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