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 6A98DCDE00E for ; Fri, 26 Jun 2026 12:31:39 +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=0klIJiYQNQ9PnKEApf54sowiYvefRGXUDdYSuJHV+hQ=; b=vFphaLOyBA4t6jiyLlrx/uLDZk bP+Jz/HM5Ftehl/xZdpsKUEBrBWZywjcn29jDwIgOaH+EPkE9ha+/KLR1C4J8p8RcazeSB7j36RsB uf50+fKtknyyHpKDBC5TjB/R1P3UuHf21HrRCogK4nDhsxY4CH7hO21wOzXSwasitxXCUay1cZbEA Hg8Hkm2t2MV3tZnuJ9v9PZH4BsEBe/LGVZyBthFIeqQF7O5MBR3fEmJYkwD4V2l6LKx8kjtviOjHB C1VCqdtaoP3Ne5A2pAFCaZkGEUeCh290x4wTpZnMcsb2Rj3mPa8FRrgJeAb5c/COYJcUEPjFtBu0q 1N/DmGXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd5iW-0000000BJNC-1xyc; Fri, 26 Jun 2026 12:31:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd5iT-0000000BJMZ-3vx2 for linux-arm-kernel@lists.infradead.org; Fri, 26 Jun 2026 12:31:31 +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 95FCE1F91; Fri, 26 Jun 2026 05:31:21 -0700 (PDT) Received: from arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F03A63F905; Fri, 26 Jun 2026 05:31:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1782477086; bh=tqFkPrKngbGi7F0q/LI40ZThdY9KNHFk+D0fm50gQjw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HVhLEjmND/1ppqrylbSCf40EEwgAUbq5bha46ZrHXo88poshwImABCbxO9rYR9eu/ YnAwzhsKmnpUI4/jHaBBTiRi6FRGkjIfvgb0O/CdDl5OI5ljJvMs0S9x56bw3RU1H5 Cgx9DuIB4SiJIaJJuQFAr3kCmt51EDfErGH0kZ2w= Date: Fri, 26 Jun 2026 13:31:22 +0100 From: Catalin Marinas To: Anshuman Khandual Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Ryan Roberts , David Hildenbrand , linux-kernel@vger.kernel.org, Ben Hutchings Subject: Re: [PATCH] arm64/mm: Optimize TLB flush in unmap_hotplug_[pmd|pud]_range() Message-ID: References: <20260626012845.475959-1-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260626012845.475959-1-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260626_053130_102065_120BCF93 X-CRM114-Status: UNSURE ( 9.63 ) 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 Fri, Jun 26, 2026 at 02:28:45AM +0100, Anshuman Khandual wrote: > flush_tlb_kernel_range() could flush down an entire block mapping just with > a single PAGE_SIZE stride. This capability was being used umapping PMD and > PUD based block mappings in unmap_hotplug_[pmd|pud]_range(). > > But later on the commit 48478b9f7913 > ("arm64/mm: Enable batched TLB flush in unmap_hotplug_range()") replaced > this PAGE_SIZE stride with [PMD|PUD]_SIZE strides, hence forcing multiple > PAGE_SIZE stride based TLB flushes on platforms where TLB range operation > is not supported. Revert back to the earlier TLB behaviour along with the > required comments that were dropped earlier. > > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Ryan Roberts > Cc: David Hildenbrand > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Reported-by: Ben Hutchings > Closes: https://lore.kernel.org/all/b0d5836032ce3135bfc473f6bff791306d086925.camel@decadent.org.uk/ > Fixes: 48478b9f7913 ("arm64/mm: Enable batched TLB flush in unmap_hotplug_range()") > Signed-off-by: Anshuman Khandual Reviewed-by: Catalin Marinas