From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AB4D1E492D for ; Mon, 10 Nov 2025 08:15:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762762542; cv=none; b=n2BI26bG9ohobo0G21npLSqN6IoDqZPDRlakKxbovCaejSEACJi1Z3MKz4CAfNpnUDCFU6ULfG+iNWPpYqjdHupxjQMcIMCjrxKZXKLo5B+hAdQP19GX9QPCM1Gsd/EwsIgdfzAgC3SynLOmQf3RGhi4p41191zvLwUcgpIipE0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762762542; c=relaxed/simple; bh=EB68nTn49IclqUIoy5cUu43IB3Zi67orMQO7viV0y30=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eEsW2mxnfl4c3sdtklhFFDNUIagU082KdvzGBJodj/oMKJkTIyUEfiEpBMsS8KoEmRXaa1UvgeemFC4gBpJG1RxeabFw2VNCwFwrRTLj9UZlTVkneTiSjobN0m66fSrSKIIolaqrTA22KiwOT6toQQsEYwDyWP4LMcafshhx0/A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=SIh5EDUr; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="SIh5EDUr" Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 5A9MiHpi019248; Mon, 10 Nov 2025 08:15:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=hzyLIDpEU237YrW6m u0z/yI7P9Nuayy1I0OaCOxC8Us=; b=SIh5EDUrxXQKeU1OU1SaNgI3N6Pm2FKoK g8KLCh756Ux6zc72iiSAYMBl4FGdIhNmk16heG6nOqNuXwitCQRQbKSeA0pROIZL x9ZHtFx2Py4xp/9kcYCD4xlGoSj/b1Wlc5n8UV9yAlarYzTIFUTwRabeQ6OR4xRa sCqA91OVI061aiz91dfXhBkcv29DDVwYg+9dAXqSw/OvF6ACepk8BPGyP3gVrlMq 30vkLUj3FchRF0RvfAuTXDbICbFGkijX2DmbF0cdVAZZuqvGxPstG+eHIScFK9zq c1D3kao68OKKGCscck7wXookKBJH4yP8mpmR3HnJ+46ACWvTK2khA== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4a9wgwp570-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Nov 2025 08:15:26 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 5AA4oVjJ008197; Mon, 10 Nov 2025 08:15:26 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4aah6mmka8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 10 Nov 2025 08:15:25 +0000 Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5AA8FNLa47645180 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 10 Nov 2025 08:15:24 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DB7432004B; Mon, 10 Nov 2025 08:15:23 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 14D8920040; Mon, 10 Nov 2025 08:15:20 +0000 (GMT) Received: from li-c9696b4c-3419-11b2-a85c-f9edc3bf8a84.ibm.com.com (unknown [9.61.93.35]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTP; Mon, 10 Nov 2025 08:15:19 +0000 (GMT) From: Nilay Shroff To: linux-block@vger.kernel.org Cc: ming.lei@redhat.com, hch@lst.de, axboe@kernel.dk, yi.zhang@redhat.com, czhong@redhat.com, yukuai@fnnas.com, gjoyce@ibm.com Subject: [PATCHv4 4/5] block: use {alloc|free}_sched data methods Date: Mon, 10 Nov 2025 13:44:51 +0530 Message-ID: <20251110081457.1006206-5-nilay@linux.ibm.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251110081457.1006206-1-nilay@linux.ibm.com> References: <20251110081457.1006206-1-nilay@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: q7xYj2kv5_XTwLS9JsgLl95FEDJwhm0z X-Proofpoint-ORIG-GUID: q7xYj2kv5_XTwLS9JsgLl95FEDJwhm0z X-Authority-Analysis: v=2.4 cv=VMPQXtPX c=1 sm=1 tr=0 ts=69119f1e cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=6UeiqGixMTsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VnNF1IyMAAAA:8 a=BHJ_uGNgmAg05V-1cPgA:9 a=cPQSjfK2_nFv0Q5t_7PE:22 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTA4MDAyMiBTYWx0ZWRfX1BUCtXiIyQd1 c/8mWehpZYHczSJi+5ShuGpIpplg1exEXPvAalmu/DjLXuBnvWUoGKPnQp/6knS+pCuH8jnfMGS OJOGS3ZfnoWU5ysAPprFAPoOUKipaUAEk0TK9KjOWDcyiTPxsbOaFHWYGdrognP8colpc5QUrkd xG6EZBJh86dWCaZuThMV4CqR5GO3eBTuchoEC50Cxv6hXiXH0JsD8HvF48WkqPkD+hkBdRCMNzx 9hK3D4nJPFctxWe1o9nLl080xNS7cm9xYo4qxyaHgnT0CuP1ug5dTGlazxZHsPvmz1VXKpCN9dv dkQZpvDQvYcM27pNXpJPC3XdHzKQ/zNmTNFPtUqB4Jy1TQNneIxIvrEl7gICqJLo2vbcacOv/n8 P43fWZeQ34NIIOqPPOrJdGkI3TYNWQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-11-10_03,2025-11-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 priorityscore=1501 lowpriorityscore=0 bulkscore=0 clxscore=1015 phishscore=0 spamscore=0 malwarescore=0 adultscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510240000 definitions=main-2511080022 The previous patch introduced ->alloc_sched_data and ->free_sched_data methods. This patch builds upon that by now using these methods during elevator switch and nr_hw_queue update. It's also ensured that scheduler-specific data is allocated and freed through the new callbacks outside of the ->freeze_lock and ->elevator_lock locking contexts, thereby preventing any dependency on pcpu_alloc_mutex. Signed-off-by: Nilay Shroff --- block/blk-mq-sched.c | 32 ++++++++++++++++++++++++-------- block/blk-mq-sched.h | 8 ++++++-- block/elevator.c | 34 ++++++++++++++++++++++------------ block/elevator.h | 4 +++- 4 files changed, 55 insertions(+), 23 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index c7091ea4dccd..0ea8f0004274 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -428,12 +428,17 @@ void blk_mq_free_sched_tags(struct elevator_tags *et, } void blk_mq_free_sched_res(struct elevator_resources *res, + struct elevator_type *type, struct blk_mq_tag_set *set) { if (res->et) { blk_mq_free_sched_tags(res->et, set); res->et = NULL; } + if (res->data) { + blk_mq_free_sched_data(type, res->data); + res->data = NULL; + } } void blk_mq_free_sched_res_batch(struct xarray *elv_tbl, @@ -458,7 +463,7 @@ void blk_mq_free_sched_res_batch(struct xarray *elv_tbl, WARN_ON_ONCE(1); continue; } - blk_mq_free_sched_res(&ctx->res, set); + blk_mq_free_sched_res(&ctx->res, ctx->type, set); } } } @@ -540,15 +545,24 @@ struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, return NULL; } -int blk_mq_alloc_sched_res(struct elevator_resources *res, - struct blk_mq_tag_set *set, unsigned int nr_hw_queues) +int blk_mq_alloc_sched_res(struct request_queue *q, + struct elevator_type *type, + struct elevator_resources *res, + struct blk_mq_tag_set *set, + unsigned int nr_hw_queues) { + int ret; + res->et = blk_mq_alloc_sched_tags(set, nr_hw_queues, blk_mq_default_nr_requests(set)); if (!res->et) return -ENOMEM; - return 0; + ret = blk_mq_alloc_sched_data(q, type, &res->data); + if (ret) + blk_mq_free_sched_tags(res->et, set); + + return ret; } int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl, @@ -575,19 +589,21 @@ int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl, goto out_unwind; } - ret = blk_mq_alloc_sched_res(&ctx->res, set, - nr_hw_queues); + ret = blk_mq_alloc_sched_res(q, q->elevator->type, + &ctx->res, set, nr_hw_queues); if (ret) goto out_unwind; } } return 0; + out_unwind: list_for_each_entry_continue_reverse(q, &set->tag_list, tag_set_list) { if (q->elevator) { ctx = xa_load(elv_tbl, q->id); if (ctx) - blk_mq_free_sched_res(&ctx->res, set); + blk_mq_free_sched_res(&ctx->res, + ctx->type, set); } } return ret; @@ -603,7 +619,7 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e, unsigned long i; int ret; - eq = elevator_alloc(q, e, res->et); + eq = elevator_alloc(q, e, res); if (!eq) return -ENOMEM; diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h index d38911d0d9eb..acd4f1355be6 100644 --- a/block/blk-mq-sched.h +++ b/block/blk-mq-sched.h @@ -25,8 +25,11 @@ void blk_mq_sched_free_rqs(struct request_queue *q); struct elevator_tags *blk_mq_alloc_sched_tags(struct blk_mq_tag_set *set, unsigned int nr_hw_queues, unsigned int nr_requests); -int blk_mq_alloc_sched_res(struct elevator_resources *res, - struct blk_mq_tag_set *set, unsigned int nr_hw_queues); +int blk_mq_alloc_sched_res(struct request_queue *q, + struct elevator_type *type, + struct elevator_resources *res, + struct blk_mq_tag_set *set, + unsigned int nr_hw_queues); int blk_mq_alloc_sched_res_batch(struct xarray *elv_tbl, struct blk_mq_tag_set *set, unsigned int nr_hw_queues); int blk_mq_alloc_sched_ctx_batch(struct xarray *elv_tbl, @@ -35,6 +38,7 @@ void blk_mq_free_sched_ctx_batch(struct xarray *elv_tbl); void blk_mq_free_sched_tags(struct elevator_tags *et, struct blk_mq_tag_set *set); void blk_mq_free_sched_res(struct elevator_resources *res, + struct elevator_type *type, struct blk_mq_tag_set *set); void blk_mq_free_sched_res_batch(struct xarray *et_table, struct blk_mq_tag_set *set); diff --git a/block/elevator.c b/block/elevator.c index 7fd3c547833c..67500fbbfaf0 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -121,7 +121,7 @@ static struct elevator_type *elevator_find_get(const char *name) static const struct kobj_type elv_ktype; struct elevator_queue *elevator_alloc(struct request_queue *q, - struct elevator_type *e, struct elevator_tags *et) + struct elevator_type *e, struct elevator_resources *res) { struct elevator_queue *eq; @@ -134,7 +134,8 @@ struct elevator_queue *elevator_alloc(struct request_queue *q, kobject_init(&eq->kobj, &elv_ktype); mutex_init(&eq->sysfs_lock); hash_init(eq->hash); - eq->et = et; + eq->et = res->et; + eq->elevator_data = res->data; return eq; } @@ -617,7 +618,7 @@ static void elv_exit_and_release(struct elv_change_ctx *ctx, mutex_unlock(&q->elevator_lock); blk_mq_unfreeze_queue(q, memflags); if (e) { - blk_mq_free_sched_res(&ctx->res, q->tag_set); + blk_mq_free_sched_res(&ctx->res, ctx->type, q->tag_set); kobject_put(&e->kobj); } } @@ -628,12 +629,15 @@ static int elevator_change_done(struct request_queue *q, int ret = 0; if (ctx->old) { - struct elevator_resources res = {.et = ctx->old->et}; + struct elevator_resources res = { + .et = ctx->old->et, + .data = ctx->old->elevator_data + }; bool enable_wbt = test_bit(ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT, &ctx->old->flags); elv_unregister_queue(q, ctx->old); - blk_mq_free_sched_res(&res, q->tag_set); + blk_mq_free_sched_res(&res, ctx->old->type, q->tag_set); kobject_put(&ctx->old->kobj); if (enable_wbt) wbt_enable_default(q->disk); @@ -658,7 +662,8 @@ static int elevator_change(struct request_queue *q, struct elv_change_ctx *ctx) lockdep_assert_held(&set->update_nr_hwq_lock); if (strncmp(ctx->name, "none", 4)) { - ret = blk_mq_alloc_sched_res(&ctx->res, set, set->nr_hw_queues); + ret = blk_mq_alloc_sched_res(q, ctx->type, &ctx->res, set, + set->nr_hw_queues); if (ret) return ret; } @@ -681,11 +686,12 @@ static int elevator_change(struct request_queue *q, struct elv_change_ctx *ctx) blk_mq_unfreeze_queue(q, memflags); if (!ret) ret = elevator_change_done(q, ctx); + /* * Free sched resource if it's allocated but we couldn't switch elevator. */ if (!ctx->new) - blk_mq_free_sched_res(&ctx->res, set); + blk_mq_free_sched_res(&ctx->res, ctx->type, set); return ret; } @@ -711,11 +717,12 @@ void elv_update_nr_hw_queues(struct request_queue *q, blk_mq_unfreeze_queue_nomemrestore(q); if (!ret) WARN_ON_ONCE(elevator_change_done(q, ctx)); + /* * Free sched resource if it's allocated but we couldn't switch elevator. */ if (!ctx->new) - blk_mq_free_sched_res(&ctx->res, set); + blk_mq_free_sched_res(&ctx->res, ctx->type, set); } /* @@ -729,7 +736,6 @@ void elevator_set_default(struct request_queue *q) .no_uevent = true, }; int err; - struct elevator_type *e; /* now we allow to switch elevator */ blk_queue_flag_clear(QUEUE_FLAG_NO_ELV_SWITCH, q); @@ -742,8 +748,8 @@ void elevator_set_default(struct request_queue *q) * have multiple queues or mq-deadline is not available, default * to "none". */ - e = elevator_find_get(ctx.name); - if (!e) + ctx.type = elevator_find_get(ctx.name); + if (!ctx.type) return; if ((q->nr_hw_queues == 1 || @@ -753,7 +759,7 @@ void elevator_set_default(struct request_queue *q) pr_warn("\"%s\" elevator initialization, failed %d, falling back to \"none\"\n", ctx.name, err); } - elevator_put(e); + elevator_put(ctx.type); } void elevator_set_none(struct request_queue *q) @@ -802,6 +808,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, ctx.name = strstrip(elevator_name); elv_iosched_load_module(ctx.name); + ctx.type = elevator_find_get(ctx.name); down_read(&set->update_nr_hwq_lock); if (!blk_queue_no_elv_switch(q)) { @@ -812,6 +819,9 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *buf, ret = -ENOENT; } up_read(&set->update_nr_hwq_lock); + + if (ctx.type) + elevator_put(ctx.type); return ret; } diff --git a/block/elevator.h b/block/elevator.h index e34043f6da26..3ee1d494f48a 100644 --- a/block/elevator.h +++ b/block/elevator.h @@ -33,6 +33,8 @@ struct elevator_tags { }; struct elevator_resources { + /* holds elevator data */ + void *data; /* holds elevator tags */ struct elevator_tags *et; }; @@ -185,7 +187,7 @@ ssize_t elv_iosched_store(struct gendisk *disk, const char *page, size_t count); extern bool elv_bio_merge_ok(struct request *, struct bio *); struct elevator_queue *elevator_alloc(struct request_queue *, - struct elevator_type *, struct elevator_tags *); + struct elevator_type *, struct elevator_resources *); /* * Helper functions. -- 2.51.0