From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
linux-kernel@vger.kernel.org,
linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org
Subject: Re: [PATCH] uprobe: Do not use UPROBE_SWBP_INSN as static initializer
Date: Thu, 20 Jun 2024 14:30:03 -0700 [thread overview]
Message-ID: <CAEf4BzaqgbjPfxKmzF-M7nzGroOwKikA0BM7Tnw7dKzKS+x9ZQ@mail.gmail.com> (raw)
In-Reply-To: <20240620193846.GA7165@redhat.com>
On Thu, Jun 20, 2024 at 12:40 PM Oleg Nesterov <oleg@redhat.com> wrote:
>
> On 06/20, Andrii Nakryiko wrote:
> >
> > Can we instead ask loongarch folks to rewrite it to be a constant?
> > Having this as a function call is both an inconvenience and potential
> > performance problem (a minor one, but still). I would imagine it's not
> > hard to hard-code an instruction as a constant here.
>
> I was going to ask the same question when I saw the bug report ;)
> The same for other users of larch_insn_gen_break().
>
> But I can't understand what does it do, it calls emit_break() and
> git grep -w emit_break finds nothing.
>
It's DEF_EMIT_REG0I15_FORMAT(break, break_op) in
arch/loongarch/include/asm/inst.h
A bunch of macro magic, but in the end it produces some constant
value, of course.
> Oleg.
>
next prev parent reply other threads:[~2024-06-20 21:30 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-18 19:43 [PATCH] uprobe: Do not use UPROBE_SWBP_INSN as static initializer Jiri Olsa
2024-06-20 19:00 ` Andrii Nakryiko
2024-06-20 19:38 ` Oleg Nesterov
2024-06-20 21:30 ` Andrii Nakryiko [this message]
2024-06-21 12:01 ` Oleg Nesterov
2024-06-21 13:17 ` Jiri Olsa
2024-06-27 13:44 ` Jiri Olsa
2024-06-27 14:20 ` Masami Hiramatsu
2024-06-27 15:29 ` Oleg Nesterov
2024-06-27 16:02 ` [PATCH] LoongArch: uprobes: make UPROBE_SWBP_INSN/UPROBE_XOLBP_INSN constant Oleg Nesterov
2024-06-27 16:51 ` Andrii Nakryiko
2024-06-27 17:38 ` Oleg Nesterov
2024-06-28 4:30 ` Masami Hiramatsu
2024-06-29 12:48 ` Tiezhu Yang
2024-06-29 13:38 ` Oleg Nesterov
2024-06-29 13:48 ` Huacai Chen
2024-06-29 15:03 ` [PATCH] LoongArch: make the users of larch_insn_gen_break() constant Oleg Nesterov
2024-06-30 1:43 ` Huacai Chen
2024-06-30 6:29 ` Oleg Nesterov
2024-07-01 6:22 ` Tiezhu Yang
2024-07-01 15:01 ` Huacai Chen
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