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=-14.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 33E73C2D0E2 for ; Tue, 22 Sep 2020 08:40:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E601023A69 for ; Tue, 22 Sep 2020 08:40:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600764013; bh=uP8LlFhaPiWHCdYEhWCVB84Z00tYgoS/2k9BUykxWMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dbpJ2M1oC/F99aaB7HmAsh6g5pNDLwglghIf424mDC37FtuL2CqSD4vHpmTeWW01I tMbQgBqazPEJb+AtZ/saiHTWHNhB2J3BCl3rtgoA83DjAkgWdLmgRt5V2LbTU6tvAs nnp4zDojwsn+afw2j5DGn9dWkLDcx5EyeHyZdbns= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726578AbgIVIkM (ORCPT ); Tue, 22 Sep 2020 04:40:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:39912 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726098AbgIVIkL (ORCPT ); Tue, 22 Sep 2020 04:40:11 -0400 Received: from localhost (unknown [213.57.247.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0991C23A5F; Tue, 22 Sep 2020 08:40:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600764010; bh=uP8LlFhaPiWHCdYEhWCVB84Z00tYgoS/2k9BUykxWMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UWVq1x2ENYkGpRg92zBBuodGYcxzFS0zaFc259fENQX5boCXUi74mlrsspN0MiaQb a46/C+2FwIIBZ5DYd4/HHfOYPTzJMcI1yGn5PcAkEOHwuKakzF0DIa/Z1CheaYVSJZ Hu3USgjSkwcQEnWkv5cAgs4CgbIZebVjLItpPMj4= From: Leon Romanovsky To: Christoph Hellwig , Doug Ledford , Jason Gunthorpe Cc: Maor Gottlieb , linux-rdma@vger.kernel.org Subject: [PATCH rdma-next v3 2/2] RDMA/umem: Move to allocate SG table from pages Date: Tue, 22 Sep 2020 11:39:58 +0300 Message-Id: <20200922083958.2150803-3-leon@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200922083958.2150803-1-leon@kernel.org> References: <20200922083958.2150803-1-leon@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Maor Gottlieb Remove the implementation of ib_umem_add_sg_table and instead call to __sg_alloc_table_from_pages which already has the logic to merge contiguous pages. Besides that it removes duplicated functionality, it reduces the memory consumption of the SG table significantly. Prior to this patch, the SG table was allocated in advance regardless consideration of contiguous pages. In huge pages system of 2MB page size, without this change, the SG table would contain x512 SG entries. E.g. for 100GB memory registration: Number of entries Size Before 26214400 600.0MB After 51200 1.2MB Signed-off-by: Maor Gottlieb Signed-off-by: Leon Romanovsky --- drivers/infiniband/core/umem.c | 92 +++++----------------------------- 1 file changed, 12 insertions(+), 80 deletions(-) diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c index 01b680b62846..0ef736970aba 100644 --- a/drivers/infiniband/core/umem.c +++ b/drivers/infiniband/core/umem.c @@ -63,73 +63,6 @@ static void __ib_umem_release(struct ib_device *dev, struct ib_umem *umem, int d sg_free_table(&umem->sg_head); } -/* ib_umem_add_sg_table - Add N contiguous pages to scatter table - * - * sg: current scatterlist entry - * page_list: array of npage struct page pointers - * npages: number of pages in page_list - * max_seg_sz: maximum segment size in bytes - * nents: [out] number of entries in the scatterlist - * - * Return new end of scatterlist - */ -static struct scatterlist *ib_umem_add_sg_table(struct scatterlist *sg, - struct page **page_list, - unsigned long npages, - unsigned int max_seg_sz, - int *nents) -{ - unsigned long first_pfn; - unsigned long i = 0; - bool update_cur_sg = false; - bool first = !sg_page(sg); - - /* Check if new page_list is contiguous with end of previous page_list. - * sg->length here is a multiple of PAGE_SIZE and sg->offset is 0. - */ - if (!first && (page_to_pfn(sg_page(sg)) + (sg->length >> PAGE_SHIFT) == - page_to_pfn(page_list[0]))) - update_cur_sg = true; - - while (i != npages) { - unsigned long len; - struct page *first_page = page_list[i]; - - first_pfn = page_to_pfn(first_page); - - /* Compute the number of contiguous pages we have starting - * at i - */ - for (len = 0; i != npages && - first_pfn + len == page_to_pfn(page_list[i]) && - len < (max_seg_sz >> PAGE_SHIFT); - len++) - i++; - - /* Squash N contiguous pages from page_list into current sge */ - if (update_cur_sg) { - if ((max_seg_sz - sg->length) >= (len << PAGE_SHIFT)) { - sg_set_page(sg, sg_page(sg), - sg->length + (len << PAGE_SHIFT), - 0); - update_cur_sg = false; - continue; - } - update_cur_sg = false; - } - - /* Squash N contiguous pages into next sge or first sge */ - if (!first) - sg = sg_next(sg); - - (*nents)++; - sg_set_page(sg, first_page, len << PAGE_SHIFT, 0); - first = false; - } - - return sg; -} - /** * ib_umem_find_best_pgsz - Find best HW page size to use for this MR * @@ -221,7 +154,7 @@ static struct ib_umem *__ib_umem_get(struct ib_device *device, struct mm_struct *mm; unsigned long npages; int ret; - struct scatterlist *sg; + struct scatterlist *sg = NULL; unsigned int gup_flags = FOLL_WRITE; /* @@ -276,15 +209,9 @@ static struct ib_umem *__ib_umem_get(struct ib_device *device, cur_base = addr & PAGE_MASK; - ret = sg_alloc_table(&umem->sg_head, npages, GFP_KERNEL); - if (ret) - goto vma; - if (!umem->writable) gup_flags |= FOLL_FORCE; - sg = umem->sg_head.sgl; - while (npages) { cond_resched(); ret = pin_user_pages_fast(cur_base, @@ -296,11 +223,17 @@ static struct ib_umem *__ib_umem_get(struct ib_device *device, goto umem_release; cur_base += ret * PAGE_SIZE; - npages -= ret; - - sg = ib_umem_add_sg_table(sg, page_list, ret, - dma_get_max_seg_size(device->dma_device), - &umem->sg_nents); + npages -= ret; + sg = __sg_alloc_table_from_pages( + &umem->sg_head, page_list, ret, 0, ret << PAGE_SHIFT, + dma_get_max_seg_size(device->dma_device), sg, npages, + GFP_KERNEL); + umem->sg_nents = umem->sg_head.nents; + if (IS_ERR(sg)) { + unpin_user_pages_dirty_lock(page_list, ret, 0); + ret = PTR_ERR(sg); + goto umem_release; + } } sg_mark_end(sg); @@ -322,7 +255,6 @@ static struct ib_umem *__ib_umem_get(struct ib_device *device, umem_release: __ib_umem_release(device, umem, 0); -vma: atomic64_sub(ib_umem_num_pages(umem), &mm->pinned_vm); out: free_page((unsigned long) page_list); -- 2.26.2