From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, mingo@elte.hu, paulus@samba.org,
davem@davemloft.net, fweisbec@gmail.com,
perfmon2-devel@lists.sf.net, eranian@gmail.com,
robert.richter@amd.com, acme@redhat.com,
Tejun Heo <tj@kernel.org>
Subject: Re: [RFC PATCH 1/2] perf_events: add support for per-cpu per-cgroup monitoring (v3)
Date: Fri, 10 Sep 2010 10:16:06 +0200 [thread overview]
Message-ID: <1284106566.402.26.camel@laptop> (raw)
In-Reply-To: <AANLkTimHwiXa62GhHA0hQ0AOcDaxgqRcV+O63G_qoZW8@mail.gmail.com>
On Thu, 2010-09-09 at 23:41 +0200, Stephane Eranian wrote:
> > alloc_percpu() is zalloc_percpu() in fact, memory is already cleared.
> >
> I remember thinking about this and trying to trace to the code down
> to figure this out. But it is rather complicated. If alloc_percpu() always
> clears the memory, then I think that calling is zalloc_percpu()
> would be more helpful....
pcpu_populate_chunk() in mm/percpu-vm.c does indeed do that memset, the
one in mm/percpu-km.c does not.
It is not obviously clear to me the -km allocator does indeed result in
zero filled memory.
Tejun?
next prev parent reply other threads:[~2010-09-10 8:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-09 13:09 [RFC PATCH 1/2] perf_events: add support for per-cpu per-cgroup monitoring (v3) Stephane Eranian
2010-09-09 13:52 ` Eric Dumazet
2010-09-09 21:41 ` Stephane Eranian
2010-09-10 8:16 ` Peter Zijlstra [this message]
2010-09-10 8:41 ` Tejun Heo
2010-09-10 8:52 ` [PATCH percpu#for-next] percpu: clear memory allocated with the km allocator Tejun Heo
2010-09-10 8:55 ` Peter Zijlstra
2010-09-10 16:31 ` Randy Dunlap
2010-09-10 16:45 ` Ingo Molnar
2010-09-10 23:28 ` Tejun Heo
2010-09-10 8:59 ` [RFC PATCH 1/2] perf_events: add support for per-cpu per-cgroup monitoring (v3) Stephane Eranian
2010-09-10 9:03 ` [PATCH] percpu: update comments to reflect that percpu allocations are always zero-filled Tejun Heo
2010-09-10 9:07 ` Stephane Eranian
2010-09-10 9:09 ` Eric Dumazet
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=1284106566.402.26.camel@laptop \
--to=peterz@infradead.org \
--cc=acme@redhat.com \
--cc=davem@davemloft.net \
--cc=eranian@gmail.com \
--cc=eranian@google.com \
--cc=eric.dumazet@gmail.com \
--cc=fweisbec@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulus@samba.org \
--cc=perfmon2-devel@lists.sf.net \
--cc=robert.richter@amd.com \
--cc=tj@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.