From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1CE283D75D0; Tue, 3 Mar 2026 21:49:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772574548; cv=none; b=B3zJzIuLa086NYMZNqy2Lr4r+Ulm3qEvN2yYL+bTcRmmO/TZwDF+FDxindsNiIevT/+NChrdwmFqEXLVMgJ/oHovUy1QOyGcJ4NXbWxXNOn20fOXah3v+1yW9j9d3Rqg3vdUEUIA+I/n3M2w0JYocu2g1zcByB0htyq/gr4FUek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772574548; c=relaxed/simple; bh=Tx8ArC1nfoXdrE+zu868PeLk0VTTYf+uHRPcFakUZAk=; h=Message-ID:Date:From:To:Cc:Subject; b=GbvSHXNqw+JBPf1wpqFrXrMy365stfvd+ZrAU65zprppR/PwyRaC9D7FsW+E10sGzT2Mvge6uTh/y0S5f0c9Uuqb5JRXREXgSOd+YUuIYB77iPYUeXOHq8dIwWYQhYB3m2+UUGa/vvz2GX2PyGSuHBIY7S33Vk82VZvjZpTjcJ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WakEttWs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WakEttWs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 839BBC116C6; Tue, 3 Mar 2026 21:49:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772574547; bh=Tx8ArC1nfoXdrE+zu868PeLk0VTTYf+uHRPcFakUZAk=; h=Date:From:To:Cc:Subject:From; b=WakEttWsU02s9Xhao5YRsPWBbcNpklp4k5Xo+wW5DiASuZtogdtTh/C8A+0hkwq3H FWJFMbkU+h5tPAwCFsOF50Oapz/LYlX/Qjrvd8KBGplFenDaOkt3XLpwLN6cIiUnZ/ PbIEOGClzq6ALauOG5hQ7EXl3ejxV1EG5W7ge2Cv8FA0cnO1WyWx38/R9VBbbzVGO7 F/OV+AmjZ194LKCz2SYu4ZmwSFd9j4RFvegfqqvq7txCIg0Kgt+dSgA1H43urQ2i7L 8pHMeetAMOmcbK3v/baWs45xTjur+QAWZk+6FlIQL6dKIB0G1YbaYWkOMO8oVUuUSq qOtXRKmfVM9qw== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1vxXcc-00000002tki-1gFB; Tue, 03 Mar 2026 16:49:42 -0500 Message-ID: <20260303214735.002154462@kernel.org> User-Agent: quilt/0.69 Date: Tue, 03 Mar 2026 16:47:35 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Brian Geffon , John Stultz , Ian Rogers , Suleiman Souhlal Subject: [PATCH 0/2] tracing: Read user data from futex system call trace event Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: We are looking at the performance of futexes and require a bit more information when tracing them. The two patches here extend the system call reading of user space to create specific handling of the futex system call. It now reads the user space relevant data (the addr, utime and addr2), as well as parses the flags. This adds a little smarts to the trace event as it only shows the parameters that are relevant, as well as parses utime as either a timespec or as val2 depending on the futex_op. Here's an example of the new output: futex_requeue-1431 [004] ..... 154.082233: sys_futex(uaddr: 0x7ffcadad2ff8 (0), FUTEX_WAIT, val: 0, timespec: 0x7f0785f83e90 (0.030000000)) futex_requeue-1421 [002] ..... 154.092286: sys_futex(uaddr: 0x7ffcadad2ff8 (0), FUTEX_CMP_REQUEUE, val: 3, val2: 0x7, uaddr2: 0x7ffcadad2ffc (0), val3: 0) futex_requeue-1421 [002] ..... 154.092321: sys_futex(uaddr: 0x7ffcadad2ffc (0), FUTEX_WAKE, val: 2147483647) futex_waitv-1433 [006] ..... 154.111394: sys_futex(uaddr: 0x55ed4a768554 (0), FUTEX_WAKE|FUTEX_PRIVATE_FLAG, val: 1) futex_waitv-1435 [002] ..... 154.128186: sys_futex(uaddr: 0x7f035fa40000 (0), FUTEX_WAKE, val: 1) Steven Rostedt (2): tracing: Have futex syscall trace event show specific user data tracing: Update futex syscall trace event to show more commands ---- kernel/trace/trace_syscalls.c | 370 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 367 insertions(+), 3 deletions(-)