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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C878E6895B for ; Thu, 31 Oct 2024 07:55:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 856FB6B0088; Thu, 31 Oct 2024 03:55:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8060F6B0089; Thu, 31 Oct 2024 03:55:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6CF486B008A; Thu, 31 Oct 2024 03:55:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 5202F6B0088 for ; Thu, 31 Oct 2024 03:55:17 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 0C3791A0A2A for ; Thu, 31 Oct 2024 07:55:17 +0000 (UTC) X-FDA: 82733135730.13.86BB76F Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf21.hostedemail.com (Postfix) with ESMTP id 6598E1C0008 for ; Thu, 31 Oct 2024 07:54:24 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=r57rkDgx; dkim=pass header.d=linutronix.de header.s=2020e header.b=MBi+cQkB; spf=pass (imf21.hostedemail.com: domain of bigeasy@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1730361155; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=smZJ3gWMsDVgdSzoTnaukuVPFfiZhLlX964GA+Dzwz8=; b=qNm2OKOGRBYc6uWenZScfyXNLhgyCm9HHjrTR/Y9wRG/V9tFQxGQnFkEMuYPBPWAc9nwNo 2PVnLqgkVHBVw9FOsvDm3LQ3NHBFtJDSnkruovWysP+frJDjhyFzn9t2rGtnhnrc8+L+0I tLCvpEWgY1nDXjegxNmP9aW3vYE7TVk= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=r57rkDgx; dkim=pass header.d=linutronix.de header.s=2020e header.b=MBi+cQkB; spf=pass (imf21.hostedemail.com: domain of bigeasy@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1730361155; a=rsa-sha256; cv=none; b=OBgolYeetxp2jLP77/TznZy1UeLnhNHkYtDbYtID8091zKChK0TakoGn8lA47PfkapKgXJ 7omxb4K/p0jLwOJ+y51nbVNM7HPrYO/JD9ewVE6JixMZ5piWWhOFMQS8viuvn6rsHb7h2A AngBh45HL6zocrMfIKVMrtHgJYW2pQI= Date: Thu, 31 Oct 2024 08:55:09 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1730361313; 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=smZJ3gWMsDVgdSzoTnaukuVPFfiZhLlX964GA+Dzwz8=; b=r57rkDgx2HVFzvFRmHdzOPKiNYr2WC/mCEprOskCaVU16cITkS4wBwAhrS0hXUnbgpiTlF rKfGhLeOQTShY9mnZ4Y8qL1mHuSu5xqzDZVtUEAU//NKbB6vF78MKOLBphHJMZp2TAQy5I fN2hPNtIrJ6j2Ay+AhquClKVpqYNGJdgzlDxGBwTT62/FGOIrPFBywu9r3dE+ocogDweur q+i7YBzVSpAuCop239hjgaalhoA9DqwrJbTzkCbfHxP2tbdzcpBVF+ZBOytIFNcEnHoBAe 8Trf2EbRSSH83GGch+pQIPGJlrwBvDnHqrl3PTCvv/k2++pdv/ZMEtKv6Pe/ag== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1730361313; 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=smZJ3gWMsDVgdSzoTnaukuVPFfiZhLlX964GA+Dzwz8=; b=MBi+cQkBAQDm1M1gu/pI18xCKC3V4DeEjZf4fFzBoP2Q6yoJkeeGw6GiblkENg8XrvD+YP C23QF+2m4Kfqe1AQ== From: Sebastian Andrzej Siewior To: Vlastimil Babka Cc: "Paul E. McKenney" , Marco Elver , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, sfr@canb.auug.org.au, longman@redhat.com, boqun.feng@gmail.com, cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org Subject: Re: [BUG] -next lockdep invalid wait context Message-ID: <20241031075509.hCS9Amov@linutronix.de> References: <41619255-cdc2-4573-a360-7794fc3614f7@paulmck-laptop> <66a745bb-d381-471c-aeee-3800a504f87d@paulmck-laptop> <20241031072136.JxDEfP5V@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 6598E1C0008 X-Stat-Signature: g75ryoagg5z8owmmhwbsu95oey5zw4u3 X-Rspam-User: X-HE-Tag: 1730361264-259186 X-HE-Meta: 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 +Axjjh5y 1T+zVqr7cmBEFvUidSrn3FQWFZxAAYn3QW6S/0bsM/akRm2nCQ+Dxfd3OSmrjPVdx5g8b/ah4Jc2q2FJG3S1RwqCD7j0Szjd66S/Bm58SDj5x1mPz5aQ+ZSr5FnEMzK7NhCQb9sWG0g9fFveY/BPZL1L9MU3iZ3UHfXBea7b5BiJYvEfhwzdQ0xzs531wiH0MbeJmydS3okgM3IMCl4GBtP35h6P8XVvYaPYkv03IdrJV9eeEEJ4Vnwd8FDni9TL4wG2Y X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2024-10-31 08:35:45 [+0100], Vlastimil Babka wrote: > On 10/31/24 08:21, Sebastian Andrzej Siewior wrote: > > On 2024-10-30 16:10:58 [-0700], Paul E. McKenney wrote: > >> > >> So I need to avoid calling kfree() within an smp_call_function() handler? > > > > Yes. No kmalloc()/ kfree() in IRQ context. > > However, isn't this the case that the rule is actually about hardirq context > on RT, and most of these operations that are in IRQ context on !RT become > the threaded interrupt context on RT, so they are actually fine? Or is smp > call callback a hardirq context on RT and thus it really can't do those > operations? interrupt handlers as of request_irq() are forced-threaded on RT so you can do kmalloc()/ kfree() there. smp_call_function.*() on the other hand are not threaded and invoked directly within the IRQ context. > Vlastimil > Sebastian