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 X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 463F3C2BB48 for ; Tue, 8 Dec 2020 14:04:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CDA323B3E for ; Tue, 8 Dec 2020 14:04:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729674AbgLHOEa (ORCPT ); Tue, 8 Dec 2020 09:04:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:54507 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729662AbgLHOEZ (ORCPT ); Tue, 8 Dec 2020 09:04:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607436179; 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=X6d4iuw/2zncrstw5QmGL4uRz/t+VxjNUWTz4LWJVQk=; b=DRjMUecdAfMjZsid90IY8vCM2eVJ8mWb6DLDT0+Bxw5P5VgTJ51Npc/3I8cNRQhVuBuGFB I0EUsam8pvI+zOZzy8SEF0JAnroGB8Rm8WxhFbu00D1/tnjhL/IFVblJCFiSG645yLfG2k MIjg5VG5BW23ZSqu7Uqsrr1ZRGIVcEc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-237-1yQZHnjvMACN12KejRdUFg-1; Tue, 08 Dec 2020 09:02:47 -0500 X-MC-Unique: 1yQZHnjvMACN12KejRdUFg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E3F2E858186; Tue, 8 Dec 2020 14:02:44 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-116-67.rdu2.redhat.com [10.10.116.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id A45115D9F8; Tue, 8 Dec 2020 14:02:42 +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: <955415.1607433903@warthog.procyon.org.uk> References: <955415.1607433903@warthog.procyon.org.uk> <118876.1607093975@warthog.procyon.org.uk> <2F96670A-58DC-43A6-A20E-696803F0BFBA@oracle.com> <160518586534.2277919.14475638653680231924.stgit@warthog.procyon.org.uk> To: Chuck Lever , Ard Biesheuvel Cc: dhowells@redhat.com, Bruce Fields , CIFS , Linux NFS Mailing List , Herbert Xu , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Trond Myklebust , linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org Subject: Re: Why the auxiliary cipher in gss_krb5_crypto.c? MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <959899.1607436161.1@warthog.procyon.org.uk> Date: Tue, 08 Dec 2020 14:02:41 +0000 Message-ID: <959900.1607436161@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Howells wrote: > I wonder - would it make sense to reserve two arrays of scatterlist structs > and a mutex per CPU sufficient to map up to 1MiB of pages with each array > while the krb5 service is in use? Actually, simply reserving a set per CPU is probably unnecessary. We could, say, set a minimum and a maximum on the reservations (say 2 -> 2*nr_cpus) and then allocate new ones when we run out. Then let the memory shrinker clean them up off an lru list. David