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 642D9CDB482 for ; Mon, 16 Oct 2023 16:34:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232539AbjJPQeG (ORCPT ); Mon, 16 Oct 2023 12:34:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232582AbjJPQdU (ORCPT ); Mon, 16 Oct 2023 12:33:20 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 362061FC1 for ; Mon, 16 Oct 2023 09:20:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697473213; 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=63Rq1KcfOTDhlc8whKkbAUCIQI+yHNiEHhPiU2TPE3M=; b=Ta6ASexRmus+Z9xPdN/99vf0hAa2qw2PuG27Te1IBI14E38nq8TqXFi70O86/qiVm7Y2Ch T3NuTWiOeiVQlRDo1VjxPlJI449rAHEJ2TVfGbFmKf5wRXSBaSH9342AX7ep2l5AhYlzsl yyYxwxlOfZzpoJLFQ63LmDvqMtFpJtM= 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-27-bJAGqS1LPQevnpXDvvjhEQ-1; Mon, 16 Oct 2023 12:19:55 -0400 X-MC-Unique: bJAGqS1LPQevnpXDvvjhEQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1E3DE862F4E; Mon, 16 Oct 2023 16:19:54 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.178]) by smtp.corp.redhat.com (Postfix) with ESMTP id A802825C8; Mon, 16 Oct 2023 16:19:51 +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: References: <20231013160423.2218093-1-dhowells@redhat.com> <20231013160423.2218093-9-dhowells@redhat.com> To: Jeff Layton Cc: dhowells@redhat.com, Steve French , Matthew Wilcox , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Dominique Martinet , Ilya Dryomov , Christian Brauner , linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-cachefs@redhat.com Subject: Re: [RFC PATCH 08/53] netfs: Add rsize to netfs_io_request MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2840973.1697473191.1@warthog.procyon.org.uk> Date: Mon, 16 Oct 2023 17:19:51 +0100 Message-ID: <2840974.1697473191@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org Jeff Layton wrote: > > + rreq->rsize = 4 * 1024 * 1024; > > return 0; > ... > > + rreq->rsize = 1024 * 1024; > > + > > Holy magic numbers, batman! I think this deserves a comment that > explains how you came up with these values. Actually, that should be set to something like the object size for ceph. > Also, do 9p and cifs not need this for some reason? At this point, cifs doesn't use netfslib, so that's implemented in a later patch in this series. 9p does need setting, but I haven't tested that yet. It probably needs setting to 1MiB as I think that's the maximum the 9p transport can handle. But in the case of cifs, this is actually dynamic, depending on how many credits we can obtain. The same may be true of ceph, though I'm not entirely clear on that as yet. For afs, the maximum [rw]size the protocol supports is actually something like 281350422593565 (ie. (65535-28) * (2^32-1)) minus a few bytes, but that's probably not a good idea. I might be best setting it at something like 256KiB as that's what OpenAFS uses. David