From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B3D10CEACC1 for ; Fri, 14 Nov 2025 20:06:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JOqB4C/lS20t6tPC5FIrQm+ReT0eGwkkWKV6KUVlY+c=; b=s/pM1GtC3fcno54P4wuEN+UhlT +XBltIs/vWBF+BdSXcCB/hUSuUE/MdVlO/+gEinHrGVbiUjDMtV3sFo9C3fi/DX3+VvEy/LVSzf/p uPY6kScnvy+BugrAL6RgV52Vtb8NbAR/ixKrYrKRT4UvsbIPWUqGrzErF9yZch1r7aJONlFyyQlBd rOM1KXyLw4eSKNOOkbTRJPv11MZ2X/Cw79+XIfKnYnzW+XBPDFlkS+Y/42uzaw+a3BNCf+IiIdHBt PlK5Wohig8587J+NUZc+Zo5v4pNn1iNY2slB7FezoIzBpfg4HwmGyYtQPpZnanUORsZ0KU+FKUsU4 Gz8QTYaw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vK04A-0000000D3sE-2KR7; Fri, 14 Nov 2025 20:06:42 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vK045-0000000D3rn-3DIU; Fri, 14 Nov 2025 20:06:40 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1763150795; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JOqB4C/lS20t6tPC5FIrQm+ReT0eGwkkWKV6KUVlY+c=; b=YK9eEZEalWaKmf+x8aV4nBEexkqfsmiKreG3Y2jkPgAgLWTY9R8IBAqeSpkzvcfTlK/5vT +O81wGsZ0UIeJ5jBhUw4Eoayfv/X/R8/YAkUQfbLySwBD+nR9giKh2lTUX2IuXR2sbXviX FoDaeDfQYEVnADDuXPIQ/3NYR3mHOmWH0metLgocPmrm5KlONkA2MI+xuHLeh3MThztb1A kXnDdCaO2sDMKHkhrx9itHQBX0xVNdyadNovuurLFgsetAEAqd8BZzCxmcKF/5SsAQ1SuC 9Fvj3cEHnJH7K5iz+x8gAJ7PDgm0830h9iPB4luicMqudfO8UPSUoF00Q35K7Q== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1763150795; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=JOqB4C/lS20t6tPC5FIrQm+ReT0eGwkkWKV6KUVlY+c=; b=1Zyc6PyPyhUajFuS2x9XsSMHMGTgSzQMRTnNoHUVo4zlrqPxJr60WPV70Jazg4G37kJhwh jOcgXkNRpr6vopAw== To: Andy Lutomirski , "Paul E. McKenney" Cc: Valentin Schneider , Linux Kernel Mailing List , linux-mm@kvack.org, rcu@vger.kernel.org, the arch/x86 maintainers , linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "Peter Zijlstra (Intel)" , Arnaldo Carvalho de Melo , Josh Poimboeuf , Paolo Bonzini , Arnd Bergmann , Frederic Weisbecker , Jason Baron , Steven Rostedt , Ard Biesheuvel , Sami Tolvanen , "David S. Miller" , Neeraj Upadhyay , Joel Fernandes , Josh Triplett , Boqun Feng , Uladzislau Rezki , Mathieu Desnoyers , Mel Gorman , Andrew Morton , Masahiro Yamada , Han Shen , Rik van Riel , Jann Horn , Dan Carpenter , Oleg Nesterov , Juri Lelli , Clark Williams , Yair Podemsky , Marcelo Tosatti , Daniel Wagner , Petr Tesarik , Shrikanth Hegde Subject: Re: [PATCH v7 00/31] context_tracking,x86: Defer some IPIs until a user->kernel transition In-Reply-To: <1a911310-4ca5-45a4-b9bf-5f37c6ab238e@app.fastmail.com> References: <20251114150133.1056710-1-vschneid@redhat.com> <89398bdf-4dad-4976-8eb9-1e86032c8794@paulmck-laptop> <1a911310-4ca5-45a4-b9bf-5f37c6ab238e@app.fastmail.com> Date: Fri, 14 Nov 2025 21:06:34 +0100 Message-ID: <87zf8o9y5x.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251114_120639_869650_369856F4 X-CRM114-Status: GOOD ( 12.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Nov 14 2025 at 10:45, Andy Lutomirski wrote: > But I did that test on a machine that would absolutely benefit from > the IPI suppression that the OP is talking about here, and I think it > would be really quite nice if a default distro kernel with a more or > less default distribution could be easily convinced to run a user > thread without interrupting it. It's a little bit had that NO_HZ_FULL > is still an exotic non-default thing, IMO. Feel free to help with getting it over the finish line. Feeling sad/bad (or whatever you wanted to say with 'had') does not change anything as you should know :) Thanks, tglx