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 C72E8C61DCB for ; Fri, 28 Aug 2026 15:59:11 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=MjQ31cfuQKa5k82uaGT/Cyx34wNELqTN6/K1Rh0XD+c=; b=Ko+nSnp8JL4H438zbQX+dKml6n b4JkHJhgpxzZEfaXu31lf1nY9S5AiDwMZA9W1x2wS8sPyhm/jnb8S02hB3SrFV+vkt4Sdx2WZy1ag NUGWekS3tcWegUzaZqxXId7f58psVfsJzJuKLadq9R90OAJ4mzRKMrZ8TH7SrBZ6jQ/zi5LRazTan MpFbSeztZvnK78otqlujihQe/jjU19g3OyVS17rPPUnyKeEaruB8PKZqTGSzK1Wzbj/Nt+5QALhaZ RfK8jR+YWBeln4Fm51rw8z3GptaAvSA4Mb6fGRZpA/Z1g9SIdJlFWlcak8dXLiBgZj/ivoqFSo4/7 WnRelDeA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzyyv-00000006A1m-2hJT; Fri, 28 Aug 2026 15:59:05 +0000 Received: from galois.linutronix.de ([2a0a:51c0:0:12e:550::1]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzyyr-000000069yi-1gDi for linux-arm-kernel@lists.infradead.org; Fri, 28 Aug 2026 15:59:04 +0000 Date: Fri, 28 Aug 2026 17:58:42 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1787932724; 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=MjQ31cfuQKa5k82uaGT/Cyx34wNELqTN6/K1Rh0XD+c=; b=o2SzTzUsSOuV/AWS4fKiiKyn/1LhaPYC6Yfdi9fN77edZ6oncnntoZNhDlY+g5FN0uIwEw zDLTrEojOcnJRJhRQAb5HCWHd7BbTk9sIN0zPDHE7URywDDDKInIzLBonFQjkJNHVimBoL kWzGMCLwRRmRuqGEMRRmC+06LriM6fJe9MbsK+pBSojb6eX8G3SqLu20XaIhwBNbTl5OoI 9/FFI5P8JkXnl0wGKMTDSeUYaukHKz3pwoo7a0R18G6ypphqw6MC2H45rnhcZbOQ/ClAs7 vMj0j3h3AzvP+zmWK/m3B+PnqHU7/qIvx3PIK31jHYeE3+dcsciApSaUFtlioA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1787932724; 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=MjQ31cfuQKa5k82uaGT/Cyx34wNELqTN6/K1Rh0XD+c=; b=Eit7LjiABhdeRfzT4glURHG1RCeV2ZAjuv33J9ECHEaXD7arcRHH/58kzIbGZWU8KSPYLR Vh8qqix9q1P5ueBA== From: Sebastian Andrzej Siewior To: Peter Zijlstra Cc: David Stevens , Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Andrew Morton , Dave Chinner , Qi Zheng , Roman Gushchin , Muchun Song , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Uladzislau Rezki , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Clark Williams , suleiman@google.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-rt-devel@lists.linux.dev Subject: Re: [RFC 06/10] Reclaim memory from blocked kernel stacks Message-ID: <20260828155842.kIh5T7iS@linutronix.de> References: <20260827232948.2520558-1-stevensd@google.com> <20260827232948.2520558-7-stevensd@google.com> <20260828133620._x2XfJR_@linutronix.de> <20260828135947.GU776954@noisy.programming.kicks-ass.net> <20260828142552.GN788244@noisy.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260828142552.GN788244@noisy.programming.kicks-ass.net> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260828_085901_575495_10AB0E5A X-CRM114-Status: UNSURE ( 8.40 ) X-CRM114-Notice: Please train this message. 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 2026-08-28 16:25:52 [+0200], Peter Zijlstra wrote: > Taking faults on the task-stack is not going to work. That fault will > happen while you have locks held and IRQs disabled. Ideally, it'll > happen when you're knee deep in the allocator. > > That fault will then again call the allocator to allocator your stack > page, and... indeed. So I do have a few ideas floating around but I leave it at it. Sebastian