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 BEE101F7085 for ; Tue, 21 Jan 2025 20:57:18 +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=1737493038; cv=none; b=AoFmoDsS3IbiTZr6dwJpJ6JkWR5wscYzq0pz1kPMapkjRsZnYhijwcNYJvRoVff1UU/5jM7Sm9N2/o+Ii4Px+5daYDszC+xvjah6cyXS3h2ep//xb0SXrEg3Wy4cjnwzCsiCM0K28P4DqTWMzO99GBpAZvRSB0tthhkdELayUxA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737493038; c=relaxed/simple; bh=iy5ayQCBkSLoo28hUaG/C/EwUnPzr1Ov8PvPCFvLQYk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rA/MdV587HBSNHm98Mo/w/uNioLTUBIVvmD4vqakWyelpM2moc75+wybiM+3EAFAEztyEZCn8HNzViZL6eUKq+pHlQnD0w7u5y2HIZrxVMmGZgcog+1ZWejc+7qtH7T9lqW/BP+LrlEAzb9D4j4+l8N91X828kf4kP+7XXHR/r0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kv821Ms0; 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="Kv821Ms0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCD72C4CEDF; Tue, 21 Jan 2025 20:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737493038; bh=iy5ayQCBkSLoo28hUaG/C/EwUnPzr1Ov8PvPCFvLQYk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Kv821Ms05lyH7YhpK7wsCFeTlAsKKy8iKpSLfpxP4Jl5+h2Eih7OaGuU13zGlPzj2 AmliDiYfrDUiRjFUOaKZ++E0y8K6iTMyE8HgtsVBe3kwexhj40ULZDh3gNOaQwrT+F TtvQPWetIm+ceQOuQvyg2xEetCggQxlcXJtFljd6GBBRy4qiNyXX4/PTF9zZ+5IGqU Kkbm6neVTBXbqjVs2sE2xJufGiIUgw/m2B0sYpxe3To6G/oe+Gt7JQrWsuoufNLGgW F4zUJbUNcNiJjLVURnZDwTdrohAHk5wZKK1UPLR2jKpAptbNTgheRVYzA26AdkXZOv IOlNWcKEbIUUA== Date: Tue, 21 Jan 2025 21:57:12 +0100 From: Ingo Molnar To: Mathieu Desnoyers Cc: Michael Jeanson , Linus Torvalds , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Shrikanth Hegde , Tejun Heo Subject: Re: [GIT PULL v2] Scheduler enhancements for v6.14 Message-ID: References: Precedence: bulk X-Mailing-List: linux-kernel@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: * Mathieu Desnoyers wrote: > > > Since I booted the scheduler tree on generic desktops and it was > > > tested on other systems as well and nothing appeared to be > > > broken, I presume RSEQ_FLAG_UNREGISTER is used only in libc > > > syscall-testcases and in specific applications? > > > > Nowadays, rseq unregistration is used by specialized applications > > (e.g. tcmalloc) which disable glibc rseq support with the glibc > > tunable and register it themselves. > > (GLIBC_TUNABLES=glibc.pthread.rseq=0) > > > > A recent glibc (2.35+) don't use explicit rseq unregistration, it's > > unregistered implicitly when the thread exits. > > > > I'll make a note to add a test case for > > GLIBC_TUNABLES=glibc.pthread.rseq=0 in the rseq selftests and > > librseq to improve test coverage when using a recent glibc. > > > > We have all the code in there to use rseq unregistration, but it is > > skipped when glibc 2.35+ is handling the registration. > > It turns out that it is covered by both librseq and glibc tests, just > not by the kernel rseq selftests: > > librseq test: tests/syscall_errors_test.c > glibc test: sysdeps/unix/sysv/linux/tst-rseq-disable.c > > We should import the librseq test into the kernel rseq selftests as > well. CCing Michael Jeanson who will take care of this. Thank you! Linus just pulled the v2 pull request, so all should be good upstream. Ingo