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From: Peter Zijlstra <peterz@infradead.org>
To: Alexei Starovoitov <ast@fb.com>
Cc: "David S. Miller" <davem@davemloft.net>,
	Ingo Molnar <mingo@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Wang Nan <wangnan0@huawei.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Brendan Gregg <brendan.d.gregg@gmail.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 1/3] perf: generalize perf_callchain
Date: Thu, 25 Feb 2016 17:48:47 +0100	[thread overview]
Message-ID: <20160225164847.GT6356@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <56CF2DCE.5010501@fb.com>

On Thu, Feb 25, 2016 at 08:37:34AM -0800, Alexei Starovoitov wrote:
> On 2/25/16 6:18 AM, Peter Zijlstra wrote:

> >>  arch/x86/include/asm/stacktrace.h |  2 +-
> >>  arch/x86/kernel/cpu/perf_event.c  |  4 ++--
> >>  arch/x86/kernel/dumpstack.c       |  6 ++++--
> >>  arch/x86/kernel/stacktrace.c      | 18 +++++++++++-------
> >>  arch/x86/oprofile/backtrace.c     |  3 ++-
> >>  include/linux/perf_event.h        | 13 +++++++++++--
> >>  kernel/events/callchain.c         | 32 ++++++++++++++++++++------------
> >>  kernel/events/internal.h          |  2 --
> >>  8 files changed, 51 insertions(+), 29 deletions(-)
> >
> >And at the very least this should have had a note that it doesn't break
> >all the other archs that implement perf-callchain stuff.
> 
> the cross-arch interface is two weak functions
> perf_callchain_kernel() and perf_callchain_user()
> and back into generic via perf_callchain_store().
> Nothing changes there. The code speaks for itself.
> "non-x86 archs are not broken" would be a silly comment.

No, a diffstat like that immediately makes me wonder if you've even
bothered looking at !x86.

A statement to this effect would've shown you did indeed consider it.

  parent reply	other threads:[~2016-02-25 16:49 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-18  3:58 [PATCH net-next 0/3] bpf_get_stackid() and stack_trace map Alexei Starovoitov
2016-02-18  3:58 ` [PATCH net-next 1/3] perf: generalize perf_callchain Alexei Starovoitov
2016-02-25 14:18   ` Peter Zijlstra
2016-02-25 16:37     ` Alexei Starovoitov
2016-02-25 16:45       ` Peter Zijlstra
2016-02-25 16:48       ` Peter Zijlstra [this message]
2016-02-25 16:47   ` Peter Zijlstra
2016-02-25 17:27     ` Alexei Starovoitov
2016-02-18  3:58 ` [PATCH net-next 2/3] bpf: introduce BPF_MAP_TYPE_STACK_TRACE Alexei Starovoitov
2016-02-25 14:23   ` Peter Zijlstra
2016-02-25 16:42     ` Alexei Starovoitov
2016-02-25 16:50       ` Peter Zijlstra
2016-02-18  3:58 ` [PATCH net-next 3/3] samples/bpf: offwaketime example Alexei Starovoitov
2016-02-20  5:25 ` [PATCH net-next 0/3] bpf_get_stackid() and stack_trace map David Miller
2016-02-25 14:24   ` Peter Zijlstra
2016-02-25 16:44     ` David Miller

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