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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00027FA3742 for ; Fri, 28 Oct 2022 16:49:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229761AbiJ1QtJ (ORCPT ); Fri, 28 Oct 2022 12:49:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230236AbiJ1Qsv (ORCPT ); Fri, 28 Oct 2022 12:48:51 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36CC6148FDD for ; Fri, 28 Oct 2022 09:47:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666975663; 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=lINxhsqMpOdjiC2dtBaOrXCk/sAH+QCARq0KZ4Gkpt0=; b=Yg7/2nmQt7VDXm1h8uzOcJ+ZoSi3y7ryV2VYvUuSi+UX3eBHTwqzqo3tiORKM4y/ZavoI/ QertnPapMx2p33nPCUEFRuFUfxlpOh3QK/qJCn+Gaf8El2rboA+/Y0SAXHsqqy01zrWL8L YpUNq2Zhqk3l2Hk4d6/2lweSIDtHhEk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-226-45EZoGBPPW6yfVTL_AZnnQ-1; Fri, 28 Oct 2022 12:47:27 -0400 X-MC-Unique: 45EZoGBPPW6yfVTL_AZnnQ-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2195C88F474; Fri, 28 Oct 2022 16:45:32 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 92546492B20; Fri, 28 Oct 2022 16:45:30 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20221028151526.319681-2-willy@infradead.org> References: <20221028151526.319681-2-willy@infradead.org> <20221028151526.319681-1-willy@infradead.org> To: "Matthew Wilcox (Oracle)" Cc: dhowells@redhat.com, linux-mm@kvack.org, Uladzislau Rezki , Dave Chinner , linux-fsdevel@vger.kernel.org, Thomas Gleixner , Ira Weiny , "Fabio M. De Francesco" , Luis Chamberlain Subject: Re: [PATCH 1/1] mm: Add folio_map_local() MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <64544.1666975529.1@warthog.procyon.org.uk> Date: Fri, 28 Oct 2022 17:45:29 +0100 Message-ID: <64545.1666975529@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Matthew Wilcox (Oracle) wrote: > Some filesystems benefit from being able to map the entire folio. > On 32-bit platforms with HIGHMEM, we fall back to using vmap, which > will be slow. If it proves to be a performance problem, we can look at > optimising it in a number of ways. Here's a thought: If a highmem arch has a huge PTEs available, can you create a huge PTE to cover the folio? > @@ -426,5 +465,4 @@ static inline void folio_zero_range(struct folio *folio, > { > zero_user_segments(&folio->page, start, start + length, 0, 0); > } > - > #endif /* _LINUX_HIGHMEM_H */ Did you want to remove that blank line? David