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From: Ingo Molnar <mingo@kernel.org>
To: Alexei Starovoitov <ast@plumgrid.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	"David S. Miller" <davem@davemloft.net>,
	Wang Nan <wangnan0@huawei.com>, He Kuang <hekuang@huawei.com>,
	Kaixu Xia <xiakaixu@huawei.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 net-next] bpf: fix bpf_perf_event_read() helper
Date: Sun, 25 Oct 2015 10:21:43 +0100	[thread overview]
Message-ID: <20151025092142.GB4380@gmail.com> (raw)
In-Reply-To: <562A474E.6040401@plumgrid.com>


* Alexei Starovoitov <ast@plumgrid.com> wrote:

> On 10/23/15 5:03 AM, Peter Zijlstra wrote:
> >So the bpf_perf_event_read() returns the count value, does this not also
> >mean that returning -EINVAL here is also 'wrong'?
> >
> >I mean, sure an actual count value that high is unlikely, but its still
> >a broken interface.
> 
> Agree. that's not pretty interface. I wish I looked at it more carefully
> when it was introduced. Now it's too late to change.

So I really, really think eBPF needs to have an easy to use mechanism to phase out 
old ABI components and introducing new (better) ones!

Then old crap can be de-emphasised and eventually removed, instead of having to 
live with crap forever ...

Thanks,

	Ingo

  parent reply	other threads:[~2015-10-25  9:21 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-23  0:10 [PATCH v3 net-next] bpf: fix bpf_perf_event_read() helper Alexei Starovoitov
2015-10-23  2:21 ` Wangnan (F)
2015-10-23  2:30   ` Alexei Starovoitov
2015-10-23  3:47 ` Wangnan (F)
2015-10-23 12:03 ` Peter Zijlstra
2015-10-23 14:42   ` Alexei Starovoitov
2015-10-23 14:54     ` Peter Zijlstra
2015-10-25  9:21     ` Ingo Molnar [this message]
2015-10-25 16:23       ` Alexei Starovoitov
2015-10-26 12:32         ` Peter Zijlstra
2015-10-26 12:54           ` Wangnan (F)
2015-10-26 21:28             ` Alexei Starovoitov
2015-10-27  4:50 ` David Miller

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