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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 0BA63C433E7 for ; Fri, 16 Oct 2020 08:46:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAF9520878 for ; Fri, 16 Oct 2020 08:46:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394777AbgJPIq2 (ORCPT ); Fri, 16 Oct 2020 04:46:28 -0400 Received: from out30-43.freemail.mail.aliyun.com ([115.124.30.43]:41762 "EHLO out30-43.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394758AbgJPIqX (ORCPT ); Fri, 16 Oct 2020 04:46:23 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R151e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=alimailimapcm10staff010182156082;MF=richard.weiyang@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0UCBIdn9_1602837979; Received: from localhost(mailfrom:richard.weiyang@linux.alibaba.com fp:SMTPD_---0UCBIdn9_1602837979) by smtp.aliyun-inc.com(127.0.0.1); Fri, 16 Oct 2020 16:46:19 +0800 Date: Fri, 16 Oct 2020 16:46:19 +0800 From: Wei Yang To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org, Andrew Morton , "Michael S . Tsirkin" , Jason Wang , Pankaj Gupta Subject: Re: [PATCH v1 18/29] virtio-mem: factor out calculation of the bit number within the sb_states bitmap Message-ID: <20201016084619.GA44269@L-31X9LVDL-1304.local> Reply-To: Wei Yang References: <20201012125323.17509-1-david@redhat.com> <20201012125323.17509-19-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201012125323.17509-19-david@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 12, 2020 at 02:53:12PM +0200, David Hildenbrand wrote: >The calculation is already complicated enough, let's limit it to one >location. > >Cc: "Michael S. Tsirkin" >Cc: Jason Wang >Cc: Pankaj Gupta >Signed-off-by: David Hildenbrand Reviewed-by: Wei Yang >--- > drivers/virtio/virtio_mem.c | 20 +++++++++++++++----- > 1 file changed, 15 insertions(+), 5 deletions(-) > >diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c >index 2cc497ad8298..73ff6e9ba839 100644 >--- a/drivers/virtio/virtio_mem.c >+++ b/drivers/virtio/virtio_mem.c >@@ -327,6 +327,16 @@ static int virtio_mem_sbm_mb_states_prepare_next_mb(struct virtio_mem *vm) > _mb_id--) \ > if (virtio_mem_sbm_get_mb_state(_vm, _mb_id) == _state) > >+/* >+ * Calculate the bit number in the sb_states bitmap for the given subblock >+ * inside the given memory block. >+ */ >+static int virtio_mem_sbm_sb_state_bit_nr(struct virtio_mem *vm, >+ unsigned long mb_id, int sb_id) >+{ >+ return (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; >+} >+ > /* > * Mark all selected subblocks plugged. > * >@@ -336,7 +346,7 @@ static void virtio_mem_sbm_set_sb_plugged(struct virtio_mem *vm, > unsigned long mb_id, int sb_id, > int count) > { >- const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; >+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id); > > __bitmap_set(vm->sbm.sb_states, bit, count); > } >@@ -350,7 +360,7 @@ static void virtio_mem_sbm_set_sb_unplugged(struct virtio_mem *vm, > unsigned long mb_id, int sb_id, > int count) > { >- const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; >+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id); > > __bitmap_clear(vm->sbm.sb_states, bit, count); > } >@@ -362,7 +372,7 @@ static bool virtio_mem_sbm_test_sb_plugged(struct virtio_mem *vm, > unsigned long mb_id, int sb_id, > int count) > { >- const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; >+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id); > > if (count == 1) > return test_bit(bit, vm->sbm.sb_states); >@@ -379,7 +389,7 @@ static bool virtio_mem_sbm_test_sb_unplugged(struct virtio_mem *vm, > unsigned long mb_id, int sb_id, > int count) > { >- const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb + sb_id; >+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, sb_id); > > /* TODO: Helper similar to bitmap_set() */ > return find_next_bit(vm->sbm.sb_states, bit + count, bit) >= >@@ -393,7 +403,7 @@ static bool virtio_mem_sbm_test_sb_unplugged(struct virtio_mem *vm, > static int virtio_mem_sbm_first_unplugged_sb(struct virtio_mem *vm, > unsigned long mb_id) > { >- const int bit = (mb_id - vm->first_mb_id) * vm->nb_sb_per_mb; >+ const int bit = virtio_mem_sbm_sb_state_bit_nr(vm, mb_id, 0); > > return find_next_zero_bit(vm->sbm.sb_states, > bit + vm->nb_sb_per_mb, bit) - bit; >-- >2.26.2 -- Wei Yang Help you, Help me