From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Jiri Olsa <jolsa@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Corey Ashford <cjashfor@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@elte.hu>, Namhyung Kim <namhyung@kernel.org>,
Paul Mackerras <paulus@samba.org>,
Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [PATCHv2] perf: Fix vmalloc ring buffer free function
Date: Mon, 11 Mar 2013 17:26:33 +0100 [thread overview]
Message-ID: <1363019193.14933.14.camel@laptop> (raw)
In-Reply-To: <20130311112105.GA9737@krava.brq.redhat.com>
On Mon, 2013-03-11 at 12:21 +0100, Jiri Olsa wrote:
> > pg_nr = offset >> page_shift;
> > pg_offset = offset & (1 << page_shift) - 1;
> >
> > You just wrecked that.
> >
> > > handle->page &= rb->nr_pages - 1;
>
> here's ^^^ where the handle->page becomes 0 due to (rb->nr_pages == 0)
then that'll be &= -1, which is a nop, no?
Also, you wrecked it for anything that uses some intermediate page
order (we currently don't).
next prev parent reply other threads:[~2013-03-11 16:26 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-01 16:34 [PATCHv2] perf: Fix vmalloc ring buffer free function Jiri Olsa
2013-03-06 14:30 ` [tip:perf/urgent] " tip-bot for Jiri Olsa
2013-03-06 15:20 ` [PATCHv2] " Frederic Weisbecker
2013-03-06 15:37 ` Jiri Olsa
2013-03-06 15:40 ` Frederic Weisbecker
2013-03-11 9:40 ` Peter Zijlstra
2013-03-11 11:21 ` Jiri Olsa
2013-03-11 12:15 ` Ingo Molnar
2013-03-11 16:26 ` Peter Zijlstra [this message]
2013-03-11 16:43 ` Jiri Olsa
2013-03-11 17:44 ` Peter Zijlstra
2013-03-11 18:02 ` Jiri Olsa
2013-03-12 10:05 ` [PATCHv3] " Jiri Olsa
2013-03-12 10:27 ` Peter Zijlstra
2013-03-12 10:53 ` Jiri Olsa
2013-03-12 12:38 ` Peter Zijlstra
2013-03-12 13:52 ` Jiri Olsa
2013-03-12 15:26 ` Peter Zijlstra
2013-03-12 15:36 ` Jiri Olsa
2013-03-12 16:24 ` Peter Zijlstra
2013-03-12 17:04 ` Jiri Olsa
2013-03-13 11:15 ` Jiri Olsa
2013-03-18 19:05 ` Jiri Olsa
2013-03-19 11:46 ` Peter Zijlstra
2013-03-19 14:35 ` [PATCHv4] perf: Fix vmalloc ring buffer pages handling Jiri Olsa
2013-04-30 15:36 ` Jiri Olsa
2013-05-01 10:34 ` Ingo Molnar
2013-05-02 7:54 ` [tip:perf/urgent] " tip-bot for Jiri Olsa
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