From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 898C24BEE20; Sat, 12 Sep 2026 14:18:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789222733; cv=none; b=PpZklVM5JMmLUvANA7taSjIMjASwaiRpThSPEIRd707GVYVu1qMafyE3WU9NlmTCaptWSxUaVM9s57Jt+4OhTeVdnzo8ZOfN3JfXtz/Id9R8xgyYvj9T2cW6n/6wMGARdCQWOrVi/Oh1YN6yc7fGikMFmJHh3k5kc/r5biRhMpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789222733; c=relaxed/simple; bh=tM3gVf9hYdstMrXA0aQF1VU7VsVsn/MhoWDSfCsSsE8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dUoYfIz8b00C/drua7eES+I7n2Zd94aA9u+rdq8Y92OnrZrVL7mR5iULa7aCjLuplkeuDkQzYyuNaHAK5m+pNammPtfMFC5umacP7XxZLcPDMeCQw0DSsdOc0eWU0LV0Hc9TzIcwFtOBwz552gZwpjL9SDpTSHp1yuju1B/CpX0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xzv4CVMA; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Xzv4CVMA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C339A1F000FF; Sat, 12 Sep 2026 14:18:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789222732; bh=bt4pgyIs7L9CFrJ5XlgBItxmPyxE2m68i4ii1RI5L+4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Xzv4CVMAMSsivstEzixFpeHSYsvbzbFf10UnghqOpO6JbtVO9QI+toA5gsqc8U4v5 Q0T4KM6rrnadQ5hsLB87XjmE32ezg/KabADNMydlYeNmlWUY66j7D3KAFAApmHetg/ EJw43Ys8MLmgzDCc2KGUqUJbMjvUtnNc4YptBptA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Guixin Liu , Jens Axboe , Sasha Levin Subject: [PATCH 6.6 0647/1424] nvmet-rdma: use sbitmap to replace rsp free list Date: Sat, 12 Sep 2026 08:51:19 +0200 Message-ID: <20260912065621.779042881@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guixin Liu [ Upstream commit 40f0e5dc2f3c866bef3fccf398114b90c6136dfa ] We can use sbitmap to manage all the nvmet_rdma_rsp instead of using free lists and spinlock, and we can use an additional tag to determine whether the nvmet_rdma_rsp is extra allocated. In addition, performance has improved: 1. testing environment is local rxe rdma devie and mem-based backstore device. 2. fio command, test the average 5 times: fio -filename=/dev/nvme0n1 --ioengine=libaio -direct=1 -size=1G -name=1 -thread -runtime=60 -time_based -rw=read -numjobs=16 -iodepth=128 -bs=4k -group_reporting 3. Before: 241k IOPS, After: 256k IOPS, an increase of about 5%. Signed-off-by: Guixin Liu Reviewed-by: Jens Axboe Stable-dep-of: 0114dd303b37 ("nvmet-rdma: fix response resource leak on queue teardown") Signed-off-by: Sasha Levin --- drivers/nvme/target/rdma.c | 56 ++++++++++++++++++-------------------- 1 file changed, 27 insertions(+), 29 deletions(-) diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c index ee56cf84627e9..d964032291cbb 100644 --- a/drivers/nvme/target/rdma.c +++ b/drivers/nvme/target/rdma.c @@ -39,6 +39,8 @@ #define NVMET_RDMA_BACKLOG 128 +#define NVMET_RDMA_DISCRETE_RSP_TAG -1 + struct nvmet_rdma_srq; struct nvmet_rdma_cmd { @@ -76,7 +78,7 @@ struct nvmet_rdma_rsp { u32 invalidate_rkey; struct list_head wait_list; - struct list_head free_list; + int tag; }; enum nvmet_rdma_queue_state { @@ -99,8 +101,7 @@ struct nvmet_rdma_queue { struct nvmet_sq nvme_sq; struct nvmet_rdma_rsp *rsps; - struct list_head free_rsps; - spinlock_t rsps_lock; + struct sbitmap rsp_tags; struct nvmet_rdma_cmd *cmds; struct work_struct release_work; @@ -173,7 +174,8 @@ static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue); static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev, struct nvmet_rdma_rsp *r); static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev, - struct nvmet_rdma_rsp *r); + struct nvmet_rdma_rsp *r, + int tag); static const struct nvmet_fabrics_ops nvmet_rdma_ops; @@ -211,15 +213,12 @@ static inline bool nvmet_rdma_need_data_out(struct nvmet_rdma_rsp *rsp) static inline struct nvmet_rdma_rsp * nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue) { - struct nvmet_rdma_rsp *rsp; - unsigned long flags; + struct nvmet_rdma_rsp *rsp = NULL; + int tag; - spin_lock_irqsave(&queue->rsps_lock, flags); - rsp = list_first_entry_or_null(&queue->free_rsps, - struct nvmet_rdma_rsp, free_list); - if (likely(rsp)) - list_del(&rsp->free_list); - spin_unlock_irqrestore(&queue->rsps_lock, flags); + tag = sbitmap_get(&queue->rsp_tags); + if (tag >= 0) + rsp = &queue->rsps[tag]; if (unlikely(!rsp)) { int ret; @@ -227,13 +226,12 @@ nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue) rsp = kzalloc(sizeof(*rsp), GFP_KERNEL); if (unlikely(!rsp)) return NULL; - ret = nvmet_rdma_alloc_rsp(queue->dev, rsp); + ret = nvmet_rdma_alloc_rsp(queue->dev, rsp, + NVMET_RDMA_DISCRETE_RSP_TAG); if (unlikely(ret)) { kfree(rsp); return NULL; } - - rsp->allocated = true; } return rsp; @@ -242,17 +240,13 @@ nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue) static inline void nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp) { - unsigned long flags; - - if (unlikely(rsp->allocated)) { + if (unlikely(rsp->tag == NVMET_RDMA_DISCRETE_RSP_TAG)) { nvmet_rdma_free_rsp(rsp->queue->dev, rsp); kfree(rsp); return; } - spin_lock_irqsave(&rsp->queue->rsps_lock, flags); - list_add_tail(&rsp->free_list, &rsp->queue->free_rsps); - spin_unlock_irqrestore(&rsp->queue->rsps_lock, flags); + sbitmap_clear_bit(&rsp->queue->rsp_tags, rsp->tag); } static void nvmet_rdma_free_inline_pages(struct nvmet_rdma_device *ndev, @@ -405,7 +399,7 @@ static void nvmet_rdma_free_cmds(struct nvmet_rdma_device *ndev, } static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev, - struct nvmet_rdma_rsp *r) + struct nvmet_rdma_rsp *r, int tag) { /* NVMe CQE / RDMA SEND */ r->req.cqe = kmalloc(sizeof(*r->req.cqe), GFP_KERNEL); @@ -433,6 +427,7 @@ static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev, r->read_cqe.done = nvmet_rdma_read_data_done; /* Data Out / RDMA WRITE */ r->write_cqe.done = nvmet_rdma_write_data_done; + r->tag = tag; return 0; @@ -455,21 +450,23 @@ nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue) { struct nvmet_rdma_device *ndev = queue->dev; int nr_rsps = queue->recv_queue_size * 2; - int ret = -EINVAL, i; + int ret = -ENOMEM, i; + + if (sbitmap_init_node(&queue->rsp_tags, nr_rsps, -1, GFP_KERNEL, + NUMA_NO_NODE, false, true)) + goto out; queue->rsps = kcalloc(nr_rsps, sizeof(struct nvmet_rdma_rsp), GFP_KERNEL); if (!queue->rsps) - goto out; + goto out_free_sbitmap; for (i = 0; i < nr_rsps; i++) { struct nvmet_rdma_rsp *rsp = &queue->rsps[i]; - ret = nvmet_rdma_alloc_rsp(ndev, rsp); + ret = nvmet_rdma_alloc_rsp(ndev, rsp, i); if (ret) goto out_free; - - list_add_tail(&rsp->free_list, &queue->free_rsps); } return 0; @@ -478,6 +475,8 @@ nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue) while (--i >= 0) nvmet_rdma_free_rsp(ndev, &queue->rsps[i]); kfree(queue->rsps); +out_free_sbitmap: + sbitmap_free(&queue->rsp_tags); out: return ret; } @@ -490,6 +489,7 @@ static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue) for (i = 0; i < nr_rsps; i++) nvmet_rdma_free_rsp(ndev, &queue->rsps[i]); kfree(queue->rsps); + sbitmap_free(&queue->rsp_tags); } static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev, @@ -1464,8 +1464,6 @@ nvmet_rdma_alloc_queue(struct nvmet_rdma_device *ndev, INIT_LIST_HEAD(&queue->rsp_wait_list); INIT_LIST_HEAD(&queue->rsp_wr_wait_list); spin_lock_init(&queue->rsp_wr_wait_lock); - INIT_LIST_HEAD(&queue->free_rsps); - spin_lock_init(&queue->rsps_lock); INIT_LIST_HEAD(&queue->queue_list); queue->idx = ida_alloc(&nvmet_rdma_queue_ida, GFP_KERNEL); -- 2.53.0