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Date: Tue, 9 Apr 2024 11:01:26 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Michal =?UTF-8?B?S291dG7DvQ==?= <mkoutny@suse.com>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami
 Hiramatsu <mhiramat@kernel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@efficios.com>, Christian Brauner <brauner@kernel.org>,
 Oleg Nesterov <oleg@redhat.com>, Kent Overstreet
 <kent.overstreet@linux.dev>, Kees Cook <keescook@chromium.org>, Andrew
 Morton <akpm@linux-foundation.org>, Tycho Andersen <tandersen@netflix.com>,
 Jens Axboe <axboe@kernel.dk>, Aleksa Sarai <cyphar@cyphar.com>
Subject: Re: [PATCH 1/3] tracing: Remove dependency of saved_cmdlines_buffer
 on PID_MAX_DEFAULT
Message-ID: <20240409110126.651e94cb@gandalf.local.home>
In-Reply-To: <20240408145819.8787-2-mkoutny@suse.com>
References: <20240408145819.8787-1-mkoutny@suse.com>
	<20240408145819.8787-2-mkoutny@suse.com>
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On Mon,  8 Apr 2024 16:58:17 +0200
Michal Koutn=C3=BD <mkoutny@suse.com> wrote:

> @@ -294,7 +295,7 @@ static void __trace_find_cmdline(int pid, char comm[])
>  		return;
>  	}
> =20
> -	tpid =3D pid & (PID_MAX_DEFAULT - 1);
> +	tpid =3D pid % PID_MAP_SIZE;

Does that compile to the same? This is a fast path.

-- Steve


>  	map =3D savedcmd->map_pid_to_cmdline[tpid];
>  	if (map !=3D NO_CMDLINE_MAP) {
>  		tpid =3D savedcmd->map_cmdline_to_pid[map];