From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 134C2216E26; Mon, 16 Jun 2025 14:58:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750085912; cv=none; b=Jj064MVyT+kCRzUf51jQv4V2OdEZ17vrTCVH+z9N9fbpLnpdJHXhnMDeRmYjtACzLJ2xsJHjX7u3IiNPIV6Z/M08KKUvynPreYJAAuvieKQ+8+2qwGRCLt2x2PhN0/XlmRFUdQ34PJmevWU7nBke9d3RJVw9INTW64PO5dNvmYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750085912; c=relaxed/simple; bh=wIdiZPYyli2N4szu69CA2U7XhLnv02tXx97AcQ5lBKk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=O1cmxOMJoYvIRPmjwRC7fe4EcvD2MBVYdMKJqfrSz31RRHhBy6VS+9ETOb3dhBrgOp3bh/nloolO/we2UO8GCyVOs3jG5SZY8vGt+viOYORBctlXEUGw8/Vaa2O8og1Ie2g3lfZDWMGBe9t8Cmk+klKvnaEChpL5wlsesfCMBps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 425EB59CCB; Mon, 16 Jun 2025 14:58:22 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf09.hostedemail.com (Postfix) with ESMTPA id 237CC20034; Mon, 16 Jun 2025 14:58:20 +0000 (UTC) Date: Mon, 16 Jun 2025 10:58:19 -0400 From: Steven Rostedt To: Christoph Hellwig Cc: "Darrick J. Wong" , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton , Carlos Maiolino Subject: Re: [PATCH 00/14] xfs: Remove unused trace events Message-ID: <20250616105819.4d37b83a@batman.local.home> In-Reply-To: <20250616053119.GD1148@lst.de> References: <20250612212405.877692069@goodmis.org> <20250613150855.GQ6156@frogsfrogsfrogs> <20250613113119.24943f6d@batman.local.home> <20250616053119.GD1148@lst.de> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 237CC20034 X-Stat-Signature: xrtt3cne15mpszeso61c3wd1iqzm4pfr X-Rspamd-Server: rspamout05 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19hESC1G4pzjZZdZ9uHr9kQMXh3gtnL9xU= X-HE-Tag: 1750085900-926499 X-HE-Meta: U2FsdGVkX193XZgjGdRK5j8nHlonQUe7QYiUVCQinh20elGdhOpp7c9hBPTtm5JJvTcbS6ldHLC9sbPCyryypjBGvpBDVZTRyqY6aSqmsqGX8RgyTMQRew3KOtRbz44Ssm6cDa1nhpy1kvsyLnwEXnPHc/Wl2q2iiV0gg+OdXBl9tTiyo79whbeqEcAMxUhRlKhyjxG1ZiINHlBzkHblOiFX6YI41WsbBFKzRnurU8Vt4O3bcR5X21qvWkiDwuqVsk1cdotXm2Vt0bvpVK8HGfdsZXy7TltjDrMcdDqu/qKaALWntfOpgYVkSbn1TCR81H27Gmk8wgv7TLGDJAdRDZbXi0my8FFs On Mon, 16 Jun 2025 07:31:19 +0200 Christoph Hellwig wrote: > > I just did an analysis of this: > > > > https://lore.kernel.org/lkml/20250613104240.509ff13c@batman.local.home/T/#md81abade0df19ba9062fd51ced4458161f885ac3 > > > > A TRACE_EVENT() is about 5K, and each DEFINE_EVENT() is about 1K. > > That's really quite expensive. And you only measured the tezt/data/bss Yes. This is something I've spent a bit of time over the years trying to address. With moving a bunch of code into trace_event.c with the added expense that trace events do function calls. It looks like it's still growing as the last time I checked it was just under 5K (something around 4800 bytes) and now it's over 5K, and the tracepoint code grew 4x. I'll start looking into "why" later when I have more time to deal with this. My time budget for removing unused events has pretty much dried up. > overhead and not even the dynamic memory overhead, which is probably > a lot more. Yes, and this is another area I look to make better. It was the motivation for eventfs which saved over 20 megs of memory by having trace event files dynamically created instead of being permanent. -- Steve