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 A69F4C47DB3 for ; Thu, 1 Feb 2024 03:30:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zTLiYJODUaOBnG1uOHHMr9XWMUIVnm07TZkmrboDsr4=; b=YOVuBZVMiW35+T B/DrhfgGPiBfYjgJV0onMrriIkijqS80APaNuRBpfxcElkYd6rgliPDUo4bTawDMi+wDder7L42F7 NaM62q33NbGC/NMKVZ2BmFz9vsoFQ8/hzCEUPeZl50Ag5PNhEmHHAJEAndnpux759ji+dlNMeWBoV YHDM60CK9pTYZYP0lZ/6qcCzzzralkpBvA/x64VYXt1t+yZKvhVmzjlSyVKjo8ItnK69VXcEz5mhr a3/0m7t1pytESYZ92zcB0eoK0EM8NwbXYKj0ZdFebW74FSYecOT4maYkkfm9t70pYf5k3iGvB0oY1 tdxL8fpJVOuG80ksH6SA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVNmm-00000006Oyr-2v6K; Thu, 01 Feb 2024 03:30:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVNmj-00000006OxT-2qdB for linux-arm-kernel@lists.infradead.org; Thu, 01 Feb 2024 03:30:43 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A4B63DA7; Wed, 31 Jan 2024 19:31:21 -0800 (PST) Received: from [10.162.42.11] (a077893.blr.arm.com [10.162.42.11]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id DADF33F738; Wed, 31 Jan 2024 19:30:26 -0800 (PST) Message-ID: <08a4971e-c31d-46f7-afbc-7404bd9a293f@arm.com> Date: Thu, 1 Feb 2024 09:00:23 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC v3 12/35] mm: Call arch_swap_prepare_to_restore() before arch_swap_restore() Content-Language: en-US To: Alexandru Elisei , catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org References: <20240125164256.4147-1-alexandru.elisei@arm.com> <20240125164256.4147-13-alexandru.elisei@arm.com> From: Anshuman Khandual In-Reply-To: <20240125164256.4147-13-alexandru.elisei@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240131_193041_808803_013FA66D X-CRM114-Status: UNSURE ( 8.34 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 1/25/24 22:12, Alexandru Elisei wrote: > arm64 uses arch_swap_restore() to restore saved tags before the page is > swapped in and it's called in atomic context (with the ptl lock held). > > Introduce arch_swap_prepare_to_restore() that will allow an architecture to > perform extra work during swap in and outside of a critical section. > This will be used by arm64 to allocate a buffer in memory where to > temporarily save tags if tag storage is not available for the page being > swapped in. Just wondering if tag storage will always be unavailable for tagged pages being swapped in ? OR there are cases where allocation might not even be required ? This prepare phase needs to be outside the critical section - only because there might be memory allocations ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel