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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19900C433F5 for ; Mon, 27 Sep 2021 08:59:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 017EA6108E for ; Mon, 27 Sep 2021 08:59:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233595AbhI0JBS (ORCPT ); Mon, 27 Sep 2021 05:01:18 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3876 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233593AbhI0JBR (ORCPT ); Mon, 27 Sep 2021 05:01:17 -0400 Received: from fraeml710-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4HHxMn2wh8z67gvx; Mon, 27 Sep 2021 16:56:53 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml710-chm.china.huawei.com (10.206.15.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 27 Sep 2021 10:59:38 +0200 Received: from [10.47.85.67] (10.47.85.67) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 27 Sep 2021 09:59:37 +0100 Subject: Re: [PATCH v4 11/13] blk-mq: Refactor and rename blk_mq_free_map_and_{requests->rqs}() To: Ming Lei CC: "axboe@kernel.dk" , "linux-block@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "hare@suse.de" References: <1632472110-244938-1-git-send-email-john.garry@huawei.com> <1632472110-244938-12-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: <45c0c587-59a2-1761-e175-3920669d0bfb@huawei.com> Date: Mon, 27 Sep 2021 10:02:40 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.85.67] X-ClientProxiedBy: lhreml717-chm.china.huawei.com (10.201.108.68) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 26/09/2021 03:05, Ming Lei wrote: > On Fri, Sep 24, 2021 at 04:28:28PM +0800, John Garry wrote: >> Refactor blk_mq_free_map_and_requests() such that it can be used at many >> sites at which the tag map and rqs are freed. >> >> Also rename to blk_mq_free_map_and_rqs(), which is shorter and matches the >> alloc equivalent. >> >> Suggested-by: Ming Lei >> Signed-off-by: John Garry >> Reviewed-by: Hannes Reinecke >> --- >> block/blk-mq-tag.c | 3 +-- >> block/blk-mq.c | 40 ++++++++++++++++++++++++---------------- >> block/blk-mq.h | 4 +++- >> 3 files changed, 28 insertions(+), 19 deletions(-) >> >> diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c >> index db99f1246795..a0ecc6d88f84 100644 >> --- a/block/blk-mq-tag.c >> +++ b/block/blk-mq-tag.c >> @@ -607,8 +607,7 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, >> if (!new) >> return -ENOMEM; >> >> - blk_mq_free_rqs(set, *tagsptr, hctx->queue_num); >> - blk_mq_free_rq_map(*tagsptr, set->flags); >> + blk_mq_free_map_and_rqs(set, *tagsptr, hctx->queue_num); >> *tagsptr = new; >> } else { >> /* >> diff --git a/block/blk-mq.c b/block/blk-mq.c >> index 46772773b9c4..464ea20b9bcb 100644 >> --- a/block/blk-mq.c >> +++ b/block/blk-mq.c >> @@ -2878,15 +2878,15 @@ static bool __blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set, >> return set->tags[hctx_idx]; >> } >> >> -static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, >> - unsigned int hctx_idx) >> +void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set, >> + struct blk_mq_tags *tags, >> + unsigned int hctx_idx) >> { >> unsigned int flags = set->flags; >> >> - if (set->tags && set->tags[hctx_idx]) { >> - blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); >> - blk_mq_free_rq_map(set->tags[hctx_idx], flags); >> - set->tags[hctx_idx] = NULL; >> + if (tags) { >> + blk_mq_free_rqs(set, tags, hctx_idx); >> + blk_mq_free_rq_map(tags, flags); >> } >> } >> >> @@ -2967,8 +2967,10 @@ static void blk_mq_map_swqueue(struct request_queue *q) >> * fallback in case of a new remap fails >> * allocation >> */ >> - if (i && set->tags[i]) >> - blk_mq_free_map_and_requests(set, i); >> + if (i && set->tags[i]) { >> + blk_mq_free_map_and_rqs(set, set->tags[i], i); >> + set->tags[i] = NULL; >> + } >> >> hctx->tags = NULL; >> continue; >> @@ -3264,8 +3266,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, >> struct blk_mq_hw_ctx *hctx = hctxs[j]; >> >> if (hctx) { >> - if (hctx->tags) >> - blk_mq_free_map_and_requests(set, j); >> + blk_mq_free_map_and_rqs(set, set->tags[j], j); >> + set->tags[j] = NULL; >> blk_mq_exit_hctx(q, set, hctx, j); >> hctxs[j] = NULL; >> } >> @@ -3361,8 +3363,10 @@ static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) >> return 0; >> >> out_unwind: >> - while (--i >= 0) >> - blk_mq_free_map_and_requests(set, i); >> + while (--i >= 0) { >> + blk_mq_free_map_and_rqs(set, set->tags[i], i); >> + set->tags[i] = NULL; >> + } >> >> return -ENOMEM; >> } >> @@ -3557,8 +3561,10 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) >> return 0; >> >> out_free_mq_rq_maps: >> - for (i = 0; i < set->nr_hw_queues; i++) >> - blk_mq_free_map_and_requests(set, i); >> + for (i = 0; i < set->nr_hw_queues; i++) { >> + blk_mq_free_map_and_rqs(set, set->tags[i], i); >> + set->tags[i] = NULL; >> + } >> out_free_mq_map: >> for (i = 0; i < set->nr_maps; i++) { >> kfree(set->map[i].mq_map); >> @@ -3590,8 +3596,10 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set) >> { >> int i, j; >> >> - for (i = 0; i < set->nr_hw_queues; i++) >> - blk_mq_free_map_and_requests(set, i); >> + for (i = 0; i < set->nr_hw_queues; i++) { >> + blk_mq_free_map_and_rqs(set, set->tags[i], i); >> + set->tags[i] = NULL; >> + } > There are 5 callers in which 'set->tags[i]' is cleared, so just > wondering why you don't clear set->tags[i] at default in > blk_mq_free_map_and_rqs(). And just call __blk_mq_free_map_and_rqs() > for the only other user? blk_mq_free_map_and_rqs() is not always passed set->tags[i]: - blk_mq_tag_update_depth() calls blk_mq_free_map_and_rqs() for sched tags - __blk_mq_alloc_rq_maps() calls blk_mq_free_map_and_rqs() for shared_sbitmap_tags Function __blk_mq_free_map_and_rqs() is not public and really only intended for set->tags[i] So I did consider passing the address of the tags pointer to blk_mq_free_map_and_rqs(), like: void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set, struct blk_mq_tag **tags, unsigned int hctx_idx) { ... *tags = NULL; } But then the API becomes a bit asymmetric, as we deal with tags pointer normally: struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set, unsigned int hctx_idx, unsigned int depth); However, apart from this, I can change __blk_mq_free_map_and_rqs() to NULLify set->tags[i], as it is always passed set->tags[i]. Do you have a preference? Thanks, John