From patchwork Sun Aug 23 23:03:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Song Bao Hua (Barry Song)" X-Patchwork-Id: 11732017 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B1FC71392 for ; Sun, 23 Aug 2020 23:06:48 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7CAA72072D for ; Sun, 23 Aug 2020 23:06:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NzDtLNCP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CAA72072D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hisilicon.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Xs8m5tUiOJg/93CillRZXhm0wWaniZXsotAr/lZpek0=; b=NzDtLNCPGMv3gxRfnL/Ycwzcw QaeSHbA6MRiAYgyVsZqYKyVppBpJHDdyf4YUaovwHZw/VY2nOGF1mr64v7HDCp8Idgh44HBeYMtBo J3MJxPOunsEtPt9sfhRHduHhhFMoj4S8+Ujs/NqNRNZr02aJdmKAYbjPwc8ucoC1bIBpCft63JzQi 3VeC2TQMg/ZDgfCgnpz1oPCTI7bGpa/12aDFFdHPLd1RW+rvBKy1i4JKOYQN57xoV/eh6H2g61t5S nOUZtjI2Hpr45nyKWXGsJ76E4ANKq6pJ2y/OPttpF5LucWCffNXsLRFrDT6n8dWwVqbEpK0c5z3B+ 1m0epBwPQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k9z4N-0001Yz-PJ; Sun, 23 Aug 2020 23:06:35 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190] helo=huawei.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k9z4D-0001Ve-MF for linux-arm-kernel@lists.infradead.org; Sun, 23 Aug 2020 23:06:28 +0000 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 3584ACBCAD25DFEE183B; Mon, 24 Aug 2020 07:06:21 +0800 (CST) Received: from SWX921481.china.huawei.com (10.126.203.214) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.487.0; Mon, 24 Aug 2020 07:06:06 +0800 From: Barry Song To: , , , , , , Subject: [PATCH v8 1/3] dma-contiguous: provide the ability to reserve per-numa CMA Date: Mon, 24 Aug 2020 11:03:07 +1200 Message-ID: <20200823230309.28980-2-song.bao.hua@hisilicon.com> X-Mailer: git-send-email 2.21.0.windows.1 In-Reply-To: <20200823230309.28980-1-song.bao.hua@hisilicon.com> References: <20200823230309.28980-1-song.bao.hua@hisilicon.com> MIME-Version: 1.0 X-Originating-IP: [10.126.203.214] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200823_190626_412246_DE4B25A3 X-CRM114-Status: GOOD ( 27.33 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_MSPIKE_H4 RBL: Very Good reputation (+4) [45.249.212.190 listed in wl.mailspike.net] -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.190 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record -0.0 RCVD_IN_MSPIKE_WL Mailspike good senders X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Barry Song , Mike Rapoport , Steve Capper , Randy Dunlap , linuxarm@huawei.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Nicolas Saenz Julienne , prime.zeng@hisilicon.com, Jonathan Cameron , huangdaode@huawei.com, linux-arm-kernel@lists.infradead.org, Mike Kravetz Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Right now, drivers like ARM SMMU are using dma_alloc_coherent() to get coherent DMA buffers to save their command queues and page tables. As there is only one default CMA in the whole system, SMMUs on nodes other than node0 will get remote memory. This leads to significant latency. This patch provides per-numa CMA so that drivers like SMMU can get local memory. Tests show localizing CMA can decrease dma_unmap latency much. For instance, before this patch, SMMU on node2 has to wait for more than 560ns for the completion of CMD_SYNC in an empty command queue; with this patch, it needs 240ns only. A positive side effect of this patch would be improving performance even further for those users who are worried about performance more than DMA security and use iommu.passthrough=1 to skip IOMMU. With local CMA, all drivers can get local coherent DMA buffers. Also, this patch changes the default CONFIG_CMA_AREAS to 19 in NUMA. As 1+CONFIG_CMA_AREAS should be quite enough for most servers on the market even they enable both hugetlb_cma and pernuma_cma. 2 numa nodes: 2(hugetlb) + 2(pernuma) + 1(default global cma) = 5 4 numa nodes: 4(hugetlb) + 4(pernuma) + 1(default global cma) = 9 8 numa nodes: 8(hugetlb) + 8(pernuma) + 1(default global cma) = 17 Cc: Randy Dunlap Cc: Mike Kravetz Cc: Jonathan Cameron Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Will Deacon Cc: Robin Murphy Cc: Ganapatrao Kulkarni Cc: Catalin Marinas Cc: Nicolas Saenz Julienne Cc: Steve Capper Cc: Andrew Morton Cc: Mike Rapoport Signed-off-by: Barry Song --- -v8: * rename parameter from pernuma_cma to cma_pernuma with respect to the comments of Mike Rapoport and Randy Dunlap * if both hugetlb_cma and pernuma_cma are enabled, we may need a larger default CMA_AREAS. In numa, we set it to 19 based on the discussion with Mike Kravetz .../admin-guide/kernel-parameters.txt | 11 ++ include/linux/dma-contiguous.h | 6 ++ kernel/dma/Kconfig | 11 ++ kernel/dma/contiguous.c | 100 ++++++++++++++++-- mm/Kconfig | 3 +- 5 files changed, 120 insertions(+), 11 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bdc1f33fd3d1..8291e2e7a99c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -599,6 +599,17 @@ altogether. For more information, see include/linux/dma-contiguous.h + cma_pernuma=nn[MG] + [ARM64,KNL] + Sets the size of kernel per-numa memory area for + contiguous memory allocations. A value of 0 disables + per-numa CMA altogether. And If this option is not + specificed, the default value is 0. + With per-numa CMA enabled, DMA users on node nid will + first try to allocate buffer from the pernuma area + which is located in node nid, if the allocation fails, + they will fallback to the global default memory area. + cmo_free_hint= [PPC] Format: { yes | no } Specify whether pages are marked as being inactive when they are freed. This is used in CMO environments diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h index 03f8e98e3bcc..fe55e004f1f4 100644 --- a/include/linux/dma-contiguous.h +++ b/include/linux/dma-contiguous.h @@ -171,6 +171,12 @@ static inline void dma_free_contiguous(struct device *dev, struct page *page, #endif +#ifdef CONFIG_DMA_PERNUMA_CMA +void dma_pernuma_cma_reserve(void); +#else +static inline void dma_pernuma_cma_reserve(void) { } +#endif + #endif #endif diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 847a9d1fa634..0ddfb5510fe4 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -118,6 +118,17 @@ config DMA_CMA If unsure, say "n". if DMA_CMA + +config DMA_PERNUMA_CMA + bool "Enable separate DMA Contiguous Memory Area for each NUMA Node" + default NUMA && ARM64 + help + Enable this option to get pernuma CMA areas so that devices like + ARM64 SMMU can get local memory by DMA coherent APIs. + + You can set the size of pernuma CMA by specifying "cma_pernuma=size" + on the kernel's command line. + comment "Default contiguous memory area size:" config CMA_SIZE_MBYTES diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index cff7e60968b9..aa53384fd7dc 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -69,6 +69,19 @@ static int __init early_cma(char *p) } early_param("cma", early_cma); +#ifdef CONFIG_DMA_PERNUMA_CMA + +static struct cma *dma_contiguous_pernuma_area[MAX_NUMNODES]; +static phys_addr_t pernuma_size_bytes __initdata; + +static int __init early_cma_pernuma(char *p) +{ + pernuma_size_bytes = memparse(p, &p); + return 0; +} +early_param("cma_pernuma", early_cma_pernuma); +#endif + #ifdef CONFIG_CMA_SIZE_PERCENTAGE static phys_addr_t __init __maybe_unused cma_early_percent_memory(void) @@ -96,6 +109,34 @@ static inline __maybe_unused phys_addr_t cma_early_percent_memory(void) #endif +#ifdef CONFIG_DMA_PERNUMA_CMA +void __init dma_pernuma_cma_reserve(void) +{ + int nid; + + if (!pernuma_size_bytes) + return; + + for_each_online_node(nid) { + int ret; + char name[20]; + struct cma **cma = &dma_contiguous_pernuma_area[nid]; + + snprintf(name, sizeof(name), "pernuma%d", nid); + ret = cma_declare_contiguous_nid(0, pernuma_size_bytes, 0, 0, + 0, false, name, cma, nid); + if (ret) { + pr_warn("%s: reservation failed: err %d, node %d", __func__, + ret, nid); + continue; + } + + pr_debug("%s: reserved %llu MiB on node %d\n", __func__, + (unsigned long long)pernuma_size_bytes / SZ_1M, nid); + } +} +#endif + /** * dma_contiguous_reserve() - reserve area(s) for contiguous memory handling * @limit: End address of the reserved memory (optional, 0 for any). @@ -228,23 +269,44 @@ static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp) * @size: Requested allocation size. * @gfp: Allocation flags. * - * This function allocates contiguous memory buffer for specified device. It - * tries to use device specific contiguous memory area if available, or the - * default global one. + * tries to use device specific contiguous memory area if available, or it + * tries to use per-numa cma, if the allocation fails, it will fallback to + * try default global one. * - * Note that it byapss one-page size of allocations from the global area as - * the addresses within one page are always contiguous, so there is no need - * to waste CMA pages for that kind; it also helps reduce fragmentations. + * Note that it bypass one-page size of allocations from the per-numa and + * global area as the addresses within one page are always contiguous, so + * there is no need to waste CMA pages for that kind; it also helps reduce + * fragmentations. */ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) { +#ifdef CONFIG_DMA_PERNUMA_CMA + int nid = dev_to_node(dev); +#endif + /* CMA can be used only in the context which permits sleeping */ if (!gfpflags_allow_blocking(gfp)) return NULL; if (dev->cma_area) return cma_alloc_aligned(dev->cma_area, size, gfp); - if (size <= PAGE_SIZE || !dma_contiguous_default_area) + if (size <= PAGE_SIZE) + return NULL; + +#ifdef CONFIG_DMA_PERNUMA_CMA + if (nid != NUMA_NO_NODE && !(gfp & (GFP_DMA | GFP_DMA32))) { + struct cma *cma = dma_contiguous_pernuma_area[nid]; + struct page *page; + + if (cma) { + page = cma_alloc_aligned(cma, size, gfp); + if (page) + return page; + } + } +#endif + if (!dma_contiguous_default_area) return NULL; + return cma_alloc_aligned(dma_contiguous_default_area, size, gfp); } @@ -261,9 +323,27 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp) */ void dma_free_contiguous(struct device *dev, struct page *page, size_t size) { - if (!cma_release(dev_get_cma_area(dev), page, - PAGE_ALIGN(size) >> PAGE_SHIFT)) - __free_pages(page, get_order(size)); + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + + /* if dev has its own cma, free page from there */ + if (dev->cma_area) { + if (cma_release(dev->cma_area, page, count)) + return; + } else { + /* + * otherwise, page is from either per-numa cma or default cma + */ +#ifdef CONFIG_DMA_PERNUMA_CMA + if (cma_release(dma_contiguous_pernuma_area[page_to_nid(page)], + page, count)) + return; +#endif + if (cma_release(dma_contiguous_default_area, page, count)) + return; + } + + /* not in any cma, free from buddy */ + __free_pages(page, get_order(size)); } /* diff --git a/mm/Kconfig b/mm/Kconfig index 6c974888f86f..d75a0107f61f 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -516,13 +516,14 @@ config CMA_DEBUGFS config CMA_AREAS int "Maximum count of the CMA areas" depends on CMA + default 19 if NUMA default 7 help CMA allows to create CMA areas for particular purpose, mainly, used as device private area. This parameter sets the maximum number of CMA area in the system. - If unsure, leave the default value "7". + If unsure, leave the default value "7" in UMA and "19" in NUMA. config MEM_SOFT_DIRTY bool "Track memory changes"