From: Steven Rostedt <rostedt@goodmis.org>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Matt Mullins <mmullins@fb.com>,
hall@fb.com, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, bpf <bpf@vger.kernel.org>,
Networking <netdev@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>, Martin KaFai Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>
Subject: Re: [PATCH bpf] bpf: fix nested bpf tracepoints with per-cpu data
Date: Fri, 7 Jun 2019 03:55:28 -0400 [thread overview]
Message-ID: <20190607035528.43c0423d@oasis.local.home> (raw)
In-Reply-To: <CAEf4BzYdRGfJgQ6-Hb8NkCgUqFRVs304KE0KMfAy9vbbTOMp5g@mail.gmail.com>
On Thu, 6 Jun 2019 19:59:18 -0700
Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
> On Thu, Jun 6, 2019 at 1:17 PM Matt Mullins <mmullins@fb.com> wrote:
> >
> > BPF_PROG_TYPE_RAW_TRACEPOINTs can be executed nested on the same CPU, as
> > they do not increment bpf_prog_active while executing.
> >
> > This enables three levels of nesting, to support
> > - a kprobe or raw tp or perf event,
> > - another one of the above that irq context happens to call, and
> > - another one in nmi context
>
> Can NMIs be nested?
No, otherwise several things in the kernel will break.
-- Steve
prev parent reply other threads:[~2019-06-07 7:55 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-31 22:37 [PATCH bpf v2] bpf: preallocate a perf_sample_data per event fd Matt Mullins
2019-06-01 1:27 ` Song Liu
2019-06-01 3:12 ` Alexei Starovoitov
2019-06-03 13:08 ` Daniel Borkmann
2019-06-03 13:22 ` Daniel Borkmann
2019-06-03 22:58 ` Matt Mullins
2019-06-03 23:27 ` Alexei Starovoitov
2019-06-03 23:48 ` Daniel Borkmann
2019-06-03 23:54 ` Alexei Starovoitov
2019-06-04 0:43 ` Daniel Borkmann
2019-06-04 0:56 ` Alexei Starovoitov
2019-06-04 3:17 ` Matt Mullins
2019-06-06 18:54 ` [PATCH bpf] bpf: fix nested bpf tracepoints with per-cpu data Matt Mullins
2019-06-06 22:13 ` Jakub Kicinski
2019-06-06 22:39 ` Matt Mullins
2019-06-07 2:59 ` Andrii Nakryiko
2019-06-07 7:55 ` Steven Rostedt [this message]
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