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[2001:1ae9:1c2:4c00:726e:c10f:8833:ff22]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-57827ae3172sm11802a12.33.2024.05.21.03.04.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 May 2024 03:04:57 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Tue, 21 May 2024 12:04:55 +0200 To: Andrii Nakryiko Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org, kernel-team@meta.com Subject: Re: [PATCH bpf 2/5] bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic Message-ID: References: <20240520234720.1748918-1-andrii@kernel.org> <20240520234720.1748918-3-andrii@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240520234720.1748918-3-andrii@kernel.org> On Mon, May 20, 2024 at 04:47:17PM -0700, Andrii Nakryiko wrote: > get_pid_task() internally already calls rcu_read_lock() and > rcu_read_unlock(), so there is no point to do this one extra time. > > This is a drive-by improvements and has no correctness implications. > > Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa jirka > --- > kernel/trace/bpf_trace.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 1baaeb9ca205..6249dac61701 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -3423,9 +3423,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr > } > > if (pid) { > - rcu_read_lock(); > task = get_pid_task(find_vpid(pid), PIDTYPE_TGID); > - rcu_read_unlock(); > if (!task) { > err = -ESRCH; > goto error_path_put; > -- > 2.43.0 > >