From: Jiri Olsa <jolsa@redhat.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
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: [PATCHv3] perf: Fix vmalloc ring buffer free function
Date: Wed, 13 Mar 2013 12:15:57 +0100 [thread overview]
Message-ID: <20130313111557.GC1064@krava.brq.redhat.com> (raw)
In-Reply-To: <20130312170416.GD32001@krava.brq.redhat.com>
On Tue, Mar 12, 2013 at 06:04:16PM +0100, Jiri Olsa wrote:
> On Tue, Mar 12, 2013 at 05:24:50PM +0100, Peter Zijlstra wrote:
> > Right you are..
> >
> > How about something like the below; using that 0 << -1 is still 0.
>
> hum.. we are obviously not on the same page wrt 'confusing' ;-)
>
> looks ok, I'll test it
hi, it work's fine..
Tested-by: Jiri Olsa <jolsa@redhat.com>
>
> jirka
>
> >
> > ---
> > kernel/events/ring_buffer.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
> > index 23cb34f..e72ca70 100644
> > --- a/kernel/events/ring_buffer.c
> > +++ b/kernel/events/ring_buffer.c
> > @@ -316,7 +316,7 @@ void rb_free(struct ring_buffer *rb)
> > struct page *
> > perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff)
> > {
> > - if (pgoff > (1UL << page_order(rb)))
> > + if (pgoff > (rb->nr_pages << page_order(rb)))
> > return NULL;
> >
> > return vmalloc_to_page((void *)rb->user_page + pgoff * PAGE_SIZE);
> > @@ -336,10 +336,10 @@ static void rb_free_work(struct work_struct *work)
> > int i, nr;
> >
> > rb = container_of(work, struct ring_buffer, work);
> > - nr = 1 << page_order(rb);
> > + nr = rb->nr_pages << page_order(rb);
> >
> > base = rb->user_page;
> > - for (i = 0; i < nr + 1; i++)
> > + for (i = 0; i <= nr; i++)
> > perf_mmap_unmark_page(base + (i * PAGE_SIZE));
> >
> > vfree(base);
> > @@ -373,7 +373,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags)
> > rb->user_page = all_buf;
> > rb->data_pages[0] = all_buf + PAGE_SIZE;
just a nit pick.. in case of having just user page,
data_pages[0] holds wrong pointer, but it 'should'
be never touch in this case
next prev parent reply other threads:[~2013-03-13 11:16 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
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 [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20130313111557.GC1064@krava.brq.redhat.com \
--to=jolsa@redhat.com \
--cc=a.p.zijlstra@chello.nl \
--cc=acme@redhat.com \
--cc=cjashfor@linux.vnet.ibm.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=namhyung@kernel.org \
--cc=paulus@samba.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).