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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 B59CFC433E7 for ; Thu, 15 Oct 2020 20:24:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50A412074F for ; Thu, 15 Oct 2020 20:24:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="E5FfS1A5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732655AbgJOUYk (ORCPT ); Thu, 15 Oct 2020 16:24:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730465AbgJOUYj (ORCPT ); Thu, 15 Oct 2020 16:24:39 -0400 Received: from mail-io1-xd42.google.com (mail-io1-xd42.google.com [IPv6:2607:f8b0:4864:20::d42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A8E5C061755 for ; Thu, 15 Oct 2020 13:24:38 -0700 (PDT) Received: by mail-io1-xd42.google.com with SMTP id o4so466995iov.13 for ; Thu, 15 Oct 2020 13:24:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5SR4Lqdjut/KlVIBcf/RdwLPa9YcULCR07wpUSCL+oM=; b=E5FfS1A5g5Knjlpbx0bxzA3qScT0sfq1tgZ9/Ipw2jL8k5jp7RvqcJ+dNTPb79eo0Q jtkLYnyXE/FXIzQHm8yLOpbTNdcNJETmjfdgXRzoqJjxYP1rfxdTGMkmgR5zYzRjUxL9 ghVbTu+o++PqbSpudWwILS/u01A6UnXhk9rjdTeLoo+p/kM2O5vCcxHpImnPpo4DMvAL p9EpYv6icfzU5XzyTcgaKj0KZrGaRDVaZMh8GFhSry3yIOCFi/SBT3323pup18cW0fH0 NdC6VyhU4Sguqo3NODmEpMX528Z9fslYVk3hWXBV82gNH6tmoOj+g2dF2DrSYZrr5it/ Kysg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5SR4Lqdjut/KlVIBcf/RdwLPa9YcULCR07wpUSCL+oM=; b=c9FQKSe2GP8tRUnsITF+NddFmlf37Og319hJkhBN4mi45YjlA6lPgux8nzml6XD6+0 cRPaIhbo3UTDR7hV4SrDElG4Sx8plZBLyayiB7NqUx9enskj9C/7IHhfW3KFVJOUArNJ tnX7vsJKeW2Pd+SH9OyJdbNwf6fKGW2dSXwDSklFObEFS24zL2T2OfXdU5Wb2dg6IVRA qBE/FnGcwVSjkAzEEufpfD96HBs4dutMZMieteltITkNBR71QMPIBBaTdtf5wa2f5kYe j6UhZ41CgWUxBx9Uu/ctXpH9gvklBF3KrQ4hFo/R0SlUORXjJiBGVVlz4pKaszoC88om 3ZQg== X-Gm-Message-State: AOAM5305+vw1SwqB83RH07PSlNrlAf+nA3SEZGRkp8dhpt9CI6Pak9N+ 24LnR0eZERcJTAKeZKmm2ow+wCikBgXkW4L/RaY= X-Google-Smtp-Source: ABdhPJzuxOtEzSLiNkioEZoZNH73fhonS1xlV9hEdJOfdW3KkS0dliJZII1/RYAYMK1tJcPP1jUgGp8NWJ4BeZsvjQw= X-Received: by 2002:a02:94cd:: with SMTP id x71mr119834jah.124.1602793477776; Thu, 15 Oct 2020 13:24:37 -0700 (PDT) MIME-Version: 1.0 References: <20201012125323.17509-1-david@redhat.com> <20201012125323.17509-3-david@redhat.com> In-Reply-To: <20201012125323.17509-3-david@redhat.com> From: Pankaj Gupta Date: Thu, 15 Oct 2020 22:24:26 +0200 Message-ID: Subject: Re: [PATCH v1 02/29] virtio-mem: simplify calculation in virtio_mem_mb_state_prepare_next_mb() To: David Hildenbrand Cc: LKML , Linux MM , virtualization@lists.linux-foundation.org, Andrew Morton , "Michael S . Tsirkin" , Jason Wang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > We actually need one byte less (next_mb_id is exclusive, first_mb_id is > inclusive). Simplify. > > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: Pankaj Gupta > Signed-off-by: David Hildenbrand > --- > drivers/virtio/virtio_mem.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c > index a1f5bf7a571a..670b3faf412d 100644 > --- a/drivers/virtio/virtio_mem.c > +++ b/drivers/virtio/virtio_mem.c > @@ -257,8 +257,8 @@ static enum virtio_mem_mb_state virtio_mem_mb_get_state(struct virtio_mem *vm, > */ > static int virtio_mem_mb_state_prepare_next_mb(struct virtio_mem *vm) > { > - unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id + 1; > - unsigned long new_bytes = vm->next_mb_id - vm->first_mb_id + 2; > + unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id; > + unsigned long new_bytes = old_bytes + 1; Maybe we can avoid new_bytes & old_bytes variables, instead use single variable. Can later be used with PFN_UP/PFN_DOWN. > int old_pages = PFN_UP(old_bytes); > int new_pages = PFN_UP(new_bytes); > uint8_t *new_mb_state; 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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 8991DC433DF for ; Thu, 15 Oct 2020 20:24:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BA7C82074A for ; Thu, 15 Oct 2020 20:24:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="E5FfS1A5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA7C82074A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B6C056B0062; Thu, 15 Oct 2020 16:24:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B1D366B0068; Thu, 15 Oct 2020 16:24:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A0C696B006E; Thu, 15 Oct 2020 16:24:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0042.hostedemail.com [216.40.44.42]) by kanga.kvack.org (Postfix) with ESMTP id 72DC46B0062 for ; Thu, 15 Oct 2020 16:24:39 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 12E76362B for ; Thu, 15 Oct 2020 20:24:39 +0000 (UTC) X-FDA: 77375287878.23.leg41_3b002fb27217 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id E9D1937606 for ; Thu, 15 Oct 2020 20:24:38 +0000 (UTC) X-HE-Tag: leg41_3b002fb27217 X-Filterd-Recvd-Size: 4106 Received: from mail-io1-f68.google.com (mail-io1-f68.google.com [209.85.166.68]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Thu, 15 Oct 2020 20:24:38 +0000 (UTC) Received: by mail-io1-f68.google.com with SMTP id m17so619290ioo.1 for ; Thu, 15 Oct 2020 13:24:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5SR4Lqdjut/KlVIBcf/RdwLPa9YcULCR07wpUSCL+oM=; b=E5FfS1A5g5Knjlpbx0bxzA3qScT0sfq1tgZ9/Ipw2jL8k5jp7RvqcJ+dNTPb79eo0Q jtkLYnyXE/FXIzQHm8yLOpbTNdcNJETmjfdgXRzoqJjxYP1rfxdTGMkmgR5zYzRjUxL9 ghVbTu+o++PqbSpudWwILS/u01A6UnXhk9rjdTeLoo+p/kM2O5vCcxHpImnPpo4DMvAL p9EpYv6icfzU5XzyTcgaKj0KZrGaRDVaZMh8GFhSry3yIOCFi/SBT3323pup18cW0fH0 NdC6VyhU4Sguqo3NODmEpMX528Z9fslYVk3hWXBV82gNH6tmoOj+g2dF2DrSYZrr5it/ Kysg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5SR4Lqdjut/KlVIBcf/RdwLPa9YcULCR07wpUSCL+oM=; b=RsxcBuWyrc37Xdyb430Pa4svcDI69RDa8vPtQqW7WJEXHI4tif5OZZLKGcdqi3WTDn FcUGL+k1FCAHIEHgGk0Tdgpch5enOyw+2qUzwr/WNwBooAghQ4MW3AVKaDdXTWZUrH0r vE6DqQNAdzOOd92Fm1bVmXK3pUsK8+B4eS+Ib+8B3iYWFH84my9JZr+BFafA+cRMD+0i ApnBXh9Xt09q1suuMogdO1vn3rJfYDmrUo28Ui2LO+B2XnPF2grycZ7Np4ubbBP3L9jP 4W2VMjIKNg2CVXE0JTK/78v7/GzlTMNuYRTE8i5Znv8Uj5IbvLNMOyXfE8DOxmQn/znl xoGg== X-Gm-Message-State: AOAM531peT+mwnXUFiB7tOGq0tFUnyALCmr9gUwogbRq5kc9ogQyh619 O/33RmSBSEK+0ri5kiJ+3+1OQextsXHzMtLkMCs= X-Google-Smtp-Source: ABdhPJzuxOtEzSLiNkioEZoZNH73fhonS1xlV9hEdJOfdW3KkS0dliJZII1/RYAYMK1tJcPP1jUgGp8NWJ4BeZsvjQw= X-Received: by 2002:a02:94cd:: with SMTP id x71mr119834jah.124.1602793477776; Thu, 15 Oct 2020 13:24:37 -0700 (PDT) MIME-Version: 1.0 References: <20201012125323.17509-1-david@redhat.com> <20201012125323.17509-3-david@redhat.com> In-Reply-To: <20201012125323.17509-3-david@redhat.com> From: Pankaj Gupta Date: Thu, 15 Oct 2020 22:24:26 +0200 Message-ID: Subject: Re: [PATCH v1 02/29] virtio-mem: simplify calculation in virtio_mem_mb_state_prepare_next_mb() To: David Hildenbrand Cc: LKML , Linux MM , virtualization@lists.linux-foundation.org, Andrew Morton , "Michael S . Tsirkin" , Jason Wang Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > We actually need one byte less (next_mb_id is exclusive, first_mb_id is > inclusive). Simplify. > > Cc: "Michael S. Tsirkin" > Cc: Jason Wang > Cc: Pankaj Gupta > Signed-off-by: David Hildenbrand > --- > drivers/virtio/virtio_mem.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c > index a1f5bf7a571a..670b3faf412d 100644 > --- a/drivers/virtio/virtio_mem.c > +++ b/drivers/virtio/virtio_mem.c > @@ -257,8 +257,8 @@ static enum virtio_mem_mb_state virtio_mem_mb_get_state(struct virtio_mem *vm, > */ > static int virtio_mem_mb_state_prepare_next_mb(struct virtio_mem *vm) > { > - unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id + 1; > - unsigned long new_bytes = vm->next_mb_id - vm->first_mb_id + 2; > + unsigned long old_bytes = vm->next_mb_id - vm->first_mb_id; > + unsigned long new_bytes = old_bytes + 1; Maybe we can avoid new_bytes & old_bytes variables, instead use single variable. Can later be used with PFN_UP/PFN_DOWN. > int old_pages = PFN_UP(old_bytes); > int new_pages = PFN_UP(new_bytes); > uint8_t *new_mb_state;