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 459B0C4332F for ; Wed, 19 Oct 2022 22:23:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229836AbiJSWXq (ORCPT ); Wed, 19 Oct 2022 18:23:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230229AbiJSWXo (ORCPT ); Wed, 19 Oct 2022 18:23:44 -0400 Received: from mail-pj1-f48.google.com (mail-pj1-f48.google.com [209.85.216.48]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40EA43FA22 for ; Wed, 19 Oct 2022 15:23:44 -0700 (PDT) Received: by mail-pj1-f48.google.com with SMTP id u8-20020a17090a5e4800b002106dcdd4a0so1528680pji.1 for ; Wed, 19 Oct 2022 15:23:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cf3IxJkfIFwEhrBZgsBaHfnMYJl9CSMzf1EADx4T3qs=; b=dK1hQB/r7ChlFytUBoYkcRXZ9vkJZHGWMvWAI9919MqNHfODEUXL34HctpcDCleIwq Zner6Ro4ITWoGivbvdjUWwkKWb2amFu3zjN0uwqGqK9UVVHrKufail7MoTQpLPc0GlGV DIO4YuWm4GnJXNY5//X0KD2AqeWHFK7czmNrx915/8mN2oeJML1YiaJSWpVIaMf77NLE NFN1ZJa90cli+3lycKmnXK0mogyyBhS82gnKp8w/qcT0WfZhf8p/dChFtx4BKrpEdvHn imGIY+KX32YgqINE92YxJ36rC695rXvfyYMelKmYTe0csCHsxJmEPIfsNSRpvZZVz4AK GSXw== X-Gm-Message-State: ACrzQf0hBPDfYyitPKzRX23xn49q7T7ah4Hl3Ya0AU4IxK2eS0dDbDth y6BTbJHEAlkGgmzo9jgv2pfxpkxuOG4= X-Google-Smtp-Source: AMsMyM7mCPf2bhuWoZ+Z8DGOCDKkpZYLSpunt0duIa5b1AEp9K99qe8wOKmCd8j1v9wttsZN5LPEGw== X-Received: by 2002:a17:902:da90:b0:185:5537:f388 with SMTP id j16-20020a170902da9000b001855537f388mr11080989plx.113.1666218223721; Wed, 19 Oct 2022 15:23:43 -0700 (PDT) Received: from bvanassche-linux.mtv.corp.google.com ([2620:15c:211:201:8280:2606:af57:d34]) by smtp.gmail.com with ESMTPSA id b3-20020a170902d50300b00174d9bbeda4sm11486866plg.197.2022.10.19.15.23.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 15:23:43 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Ming Lei , Keith Busch Subject: [PATCH 05/10] block: Introduce QUEUE_FLAG_SUB_PAGE_SEGMENTS Date: Wed, 19 Oct 2022 15:23:19 -0700 Message-Id: <20221019222324.362705-6-bvanassche@acm.org> X-Mailer: git-send-email 2.38.0.413.g74048e4d9e-goog In-Reply-To: <20221019222324.362705-1-bvanassche@acm.org> References: <20221019222324.362705-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Prepare for introducing support for segments smaller than the page size one driver at a time by introducing the request queue flag QUEUE_FLAG_SUB_PAGE_SEGMENTS. Although I am not aware of any storage controller that restricts the segment size to 512 bytes, supporting 512 bytes as minimum segment size makes it easy to test small segment support on systems with PAGE_SIZE = 4096. Cc: Christoph Hellwig Cc: Ming Lei Cc: Keith Busch Signed-off-by: Bart Van Assche --- block/blk-settings.c | 10 ++++++---- include/linux/blkdev.h | 3 +++ 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/block/blk-settings.c b/block/blk-settings.c index 1cba5c2a2796..1b7687d0ece2 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -277,10 +277,12 @@ EXPORT_SYMBOL_GPL(blk_queue_max_discard_segments); **/ void blk_queue_max_segment_size(struct request_queue *q, unsigned int max_size) { - if (max_size < PAGE_SIZE) { - max_size = PAGE_SIZE; - printk(KERN_INFO "%s: set to minimum %d\n", - __func__, max_size); + unsigned int min_segment_size = blk_queue_sub_page_segments(q) ? + SECTOR_SIZE : PAGE_SIZE; + + if (max_size < min_segment_size) { + max_size = min_segment_size; + printk(KERN_INFO "%s: set to minimum %d\n", __func__, max_size); } /* see blk_queue_virt_boundary() for the explanation */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 50e358a19d98..6757f836fd57 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -579,6 +579,7 @@ struct request_queue { #define QUEUE_FLAG_HCTX_ACTIVE 28 /* at least one blk-mq hctx is active */ #define QUEUE_FLAG_NOWAIT 29 /* device supports NOWAIT */ #define QUEUE_FLAG_SQ_SCHED 30 /* single queue style io dispatch */ +#define QUEUE_FLAG_SUB_PAGE_SEGMENTS 31 /* segments smaller than one page */ #define QUEUE_FLAG_MQ_DEFAULT ((1UL << QUEUE_FLAG_IO_STAT) | \ (1UL << QUEUE_FLAG_SAME_COMP) | \ @@ -619,6 +620,8 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); #define blk_queue_pm_only(q) atomic_read(&(q)->pm_only) #define blk_queue_registered(q) test_bit(QUEUE_FLAG_REGISTERED, &(q)->queue_flags) #define blk_queue_sq_sched(q) test_bit(QUEUE_FLAG_SQ_SCHED, &(q)->queue_flags) +#define blk_queue_sub_page_segments(q) \ + test_bit(QUEUE_FLAG_SUB_PAGE_SEGMENTS, &(q)->queue_flags) extern void blk_set_pm_only(struct request_queue *q); extern void blk_clear_pm_only(struct request_queue *q);