From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>,
Jiri Olsa <olsajiri@gmail.com>, Oleg Nesterov <oleg@redhat.com>,
Andrii Nakryiko <andrii@kernel.org>, bpf <bpf@vger.kernel.org>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
Hao Luo <haoluo@google.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Alan Maguire <alan.maguire@oracle.com>,
LKML <linux-kernel@vger.kernel.org>,
linux-trace-kernel <linux-trace-kernel@vger.kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [RFC perf/core 05/11] uprobes: Add mapping for optimized uprobe trampolines
Date: Thu, 21 Nov 2024 08:02:12 -0800 [thread overview]
Message-ID: <CAADnVQJJ0WS=Y1EudjiFD8fn4zHCz6x1auaEEHaYHsP15Vks2Q@mail.gmail.com> (raw)
In-Reply-To: <20241121115353.GJ24774@noisy.programming.kicks-ass.net>
On Thu, Nov 21, 2024 at 4:17 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Wed, Nov 20, 2024 at 04:07:38PM -0800, Andrii Nakryiko wrote:
>
> > USDTs are meant to be "transparent" to the surrounding code and they
> > don't mark any clobbered registers. Technically it could be added, but
> > I'm not a fan of this.
>
> Sure. Anyway, another thing to consider is FRED, will all of this still
> matter once that lands? If FRED gets us INT3 performance close to what
> SYSCALL has, then all this work will go unused.
afaik not a single cpu in the datacenter supports FRED while
uprobe overhead is real.
imo it's worth improving performance today for existing cpus.
I suspect arm64 might benefit too. Even if arm hw does the same
amount of work for trap vs syscall the sw overhead of handling
trap is different.
I suspect that equation will apply to future FRED cpus too.
next prev parent reply other threads:[~2024-11-21 16:02 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-05 13:33 [RFC 00/11] uprobes: Add support to optimize usdt probes on x86_64 Jiri Olsa
2024-11-05 13:33 ` [RFC perf/core 01/11] uprobes: Rename arch_uretprobe_trampoline function Jiri Olsa
2024-11-05 13:33 ` [RFC perf/core 02/11] uprobes: Make copy_from_page global Jiri Olsa
2024-11-14 23:40 ` Andrii Nakryiko
2024-11-16 21:41 ` Jiri Olsa
2024-11-05 13:33 ` [RFC perf/core 03/11] uprobes: Add len argument to uprobe_write_opcode Jiri Olsa
2024-11-14 23:41 ` Andrii Nakryiko
2024-11-16 21:41 ` Jiri Olsa
2024-11-05 13:33 ` [RFC perf/core 04/11] uprobes: Add data argument to uprobe_write_opcode function Jiri Olsa
2024-11-14 23:41 ` Andrii Nakryiko
2024-11-16 21:43 ` Jiri Olsa
2024-11-05 13:33 ` [RFC perf/core 05/11] uprobes: Add mapping for optimized uprobe trampolines Jiri Olsa
2024-11-05 14:23 ` Peter Zijlstra
2024-11-05 16:33 ` Jiri Olsa
2024-11-14 23:44 ` Andrii Nakryiko
2024-11-16 21:44 ` Jiri Olsa
2024-11-19 6:06 ` Andrii Nakryiko
2024-11-19 9:13 ` Peter Zijlstra
2024-11-19 15:15 ` Jiri Olsa
2024-11-21 0:07 ` Andrii Nakryiko
2024-11-21 11:53 ` Peter Zijlstra
2024-11-21 16:02 ` Alexei Starovoitov [this message]
2024-11-21 16:34 ` Peter Zijlstra
2024-11-21 16:47 ` Alexei Starovoitov
2024-11-21 19:38 ` Mark Rutland
2024-11-14 23:44 ` Andrii Nakryiko
2024-11-16 21:44 ` Jiri Olsa
2024-11-19 6:05 ` Andrii Nakryiko
2024-11-19 15:14 ` Jiri Olsa
2024-11-21 0:10 ` Andrii Nakryiko
2024-11-05 13:34 ` [RFC perf/core 06/11] uprobes: Add uprobe syscall to speed up uprobe Jiri Olsa
2024-11-05 13:34 ` [RFC perf/core 07/11] uprobes/x86: Add support to optimize uprobes Jiri Olsa
2024-11-14 23:44 ` Andrii Nakryiko
2024-11-16 21:44 ` Jiri Olsa
2024-11-18 8:18 ` Masami Hiramatsu
2024-11-18 9:39 ` Jiri Olsa
2024-11-05 13:34 ` [RFC bpf-next 08/11] selftests/bpf: Use 5-byte nop for x86 usdt probes Jiri Olsa
2024-11-05 13:34 ` [RFC bpf-next 09/11] selftests/bpf: Add usdt trigger bench Jiri Olsa
2024-11-14 23:40 ` Andrii Nakryiko
2024-11-16 21:45 ` Jiri Olsa
2024-11-19 6:08 ` Andrii Nakryiko
2024-11-05 13:34 ` [RFC bpf-next 10/11] selftests/bpf: Add uprobe/usdt optimized test Jiri Olsa
2024-11-05 13:34 ` [RFC bpf-next 11/11] selftests/bpf: Add hit/attach/detach race optimized uprobe test Jiri Olsa
2024-11-17 11:49 ` [RFC 00/11] uprobes: Add support to optimize usdt probes on x86_64 Peter Zijlstra
2024-11-18 9:29 ` Jiri Olsa
2024-11-18 10:06 ` Mark Rutland
2024-11-19 6:13 ` Andrii Nakryiko
2024-11-21 18:18 ` Mark Rutland
2024-11-26 19:13 ` Andrii Nakryiko
2024-11-18 8:04 ` Masami Hiramatsu
2024-11-18 9:52 ` Jiri Olsa
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