From: Christoph Hellwig <hch@lst.de>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: "Darrick J. Wong" <djwong@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
linux-xfs@vger.kernel.org, Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Carlos Maiolino <cem@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 00/14] xfs: Remove unused trace events
Date: Mon, 16 Jun 2025 07:31:19 +0200 [thread overview]
Message-ID: <20250616053119.GD1148@lst.de> (raw)
In-Reply-To: <20250613113119.24943f6d@batman.local.home>
On Fri, Jun 13, 2025 at 11:31:19AM -0400, Steven Rostedt wrote:
> On Fri, 13 Jun 2025 08:08:55 -0700
> "Darrick J. Wong" <djwong@kernel.org> wrote:
>
> > On Thu, Jun 12, 2025 at 05:24:05PM -0400, Steven Rostedt wrote:
> > >
> > > Trace events take up to 5K in memory for text and meta data. I have code that
> >
> > Under what circumstances do they eat up that much memory? And is that
> > per-class? Or per-tracepoint?
>
> 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
overhead and not even the dynamic memory overhead, which is probably
a lot more.
next prev parent reply other threads:[~2025-06-16 5:31 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-12 21:24 [PATCH 00/14] xfs: Remove unused trace events Steven Rostedt
2025-06-12 21:24 ` [PATCH 01/14] xfs: tracing; Remove unused event xfs_reflink_cow_found Steven Rostedt
2025-06-13 15:38 ` Steven Rostedt
2025-06-13 23:52 ` kernel test robot
2025-06-12 21:24 ` [PATCH 02/14] xfs: Remove unused trace event xfs_attr_remove_iter_return Steven Rostedt
2025-06-16 5:26 ` Christoph Hellwig
2025-06-16 14:51 ` Steven Rostedt
2025-06-12 21:24 ` [PATCH 03/14] xfs: Remove unused event xlog_iclog_want_sync Steven Rostedt
2025-06-12 21:24 ` [PATCH 04/14] xfs: Remove unused event xfs_ioctl_clone Steven Rostedt
2025-06-12 21:24 ` [PATCH 05/14] xfs: Remove unused xfs_reflink_compare_extents events Steven Rostedt
2025-06-12 21:24 ` [PATCH 06/14] xfs: Remove unused trace event xfs_attr_rmtval_set Steven Rostedt
2025-06-12 21:24 ` [PATCH 07/14] xfs: ifdef out unused xfs_attr events Steven Rostedt
2025-06-16 5:28 ` Christoph Hellwig
2025-06-16 14:52 ` Steven Rostedt
2025-06-17 4:46 ` Christoph Hellwig
2025-06-12 21:24 ` [PATCH 08/14] xfs: Remove unused event xfs_attr_node_removename Steven Rostedt
2025-06-12 21:24 ` [PATCH 09/14] xfs: Remove unused event xfs_alloc_near_error Steven Rostedt
2025-06-12 21:24 ` [PATCH 10/14] xfs: Remove unused event xfs_alloc_near_nominleft Steven Rostedt
2025-06-12 21:24 ` [PATCH 11/14] xfs: Remove unused event xfs_pagecache_inval Steven Rostedt
2025-06-12 21:24 ` [PATCH 12/14] xfs: Remove usused xfs_end_io_direct events Steven Rostedt
2025-06-12 21:24 ` [PATCH 13/14] xfs: Only create event xfs_file_compat_ioctl when CONFIG_COMPAT is configure Steven Rostedt
2025-06-12 21:24 ` [PATCH 14/14] xfs: Change xfs_xattr_class from a TRACE_EVENT() to DECLARE_EVENT_CLASS() Steven Rostedt
2025-06-13 15:08 ` [PATCH 00/14] xfs: Remove unused trace events Darrick J. Wong
2025-06-13 15:31 ` Steven Rostedt
2025-06-16 5:31 ` Christoph Hellwig [this message]
2025-06-16 14:58 ` Steven Rostedt
2025-07-23 22:35 ` Steven Rostedt
2025-06-16 5:30 ` Christoph Hellwig
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