IOMMU Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Cc: Hillf Danton <hdanton@sina.com>,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
	linux-kernel@vger.kernel.org, ath10k@lists.infradead.org,
	davem@davemloft.net, Nicolin Chen <nicoleotsuka@gmail.com>,
	iommu@lists.linux-foundation.org, tobias.klausmann@freenet.de,
	robin.murphy@arm.com, Christoph Hellwig <hch@lst.de>,
	kvalo@codeaurora.org
Subject: Re: regression in ath10k dma allocation
Date: Tue, 20 Aug 2019 05:05:14 +0200
Message-ID: <20190820030514.GA24612@lst.de> (raw)
In-Reply-To: <acd7a4b0-fde8-1aa2-af07-2b469e5d5ca7@mni.thm.de>

Tobias, plase try this patch:

--
From 88c590a2ecafc8279388f25bfbe1ead8ea3507a6 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 20 Aug 2019 11:45:49 +0900
Subject: dma-direct: fix zone selection after an unaddressable CMA allocation

The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable.  That means we either fail
outright or dip into a small zone that might not succeed either.

Thanks to Hillf Danton for debugging this issue.

Fixes: b1d2dc009dec ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/iommu/dma-iommu.c      | 3 +++
 include/linux/dma-contiguous.h | 5 +----
 kernel/dma/contiguous.c        | 9 +++------
 kernel/dma/direct.c            | 7 ++++++-
 4 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index d991d40f797f..f68a62c3c32b 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -965,10 +965,13 @@ static void *iommu_dma_alloc_pages(struct device *dev, size_t size,
 {
 	bool coherent = dev_is_dma_coherent(dev);
 	size_t alloc_size = PAGE_ALIGN(size);
+	int node = dev_to_node(dev);
 	struct page *page = NULL;
 	void *cpu_addr;
 
 	page = dma_alloc_contiguous(dev, alloc_size, gfp);
+	if (!page)
+		page = alloc_pages_node(node, gfp, get_order(alloc_size));
 	if (!page)
 		return NULL;
 
diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h
index c05d4e661489..03f8e98e3bcc 100644
--- a/include/linux/dma-contiguous.h
+++ b/include/linux/dma-contiguous.h
@@ -160,10 +160,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
 static inline struct page *dma_alloc_contiguous(struct device *dev, size_t size,
 		gfp_t gfp)
 {
-	int node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
-	size_t align = get_order(PAGE_ALIGN(size));
-
-	return alloc_pages_node(node, gfp, align);
+	return NULL;
 }
 
 static inline void dma_free_contiguous(struct device *dev, struct page *page,
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 2bd410f934b3..e6b450fdbeb6 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -230,9 +230,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
  */
 struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
 {
-	int node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
-	size_t count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	size_t align = get_order(PAGE_ALIGN(size));
+	size_t count = size >> PAGE_SHIFT;
 	struct page *page = NULL;
 	struct cma *cma = NULL;
 
@@ -243,14 +241,12 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
 
 	/* CMA can be used only in the context which permits sleeping */
 	if (cma && gfpflags_allow_blocking(gfp)) {
+		size_t align = get_order(size);
 		size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
 
 		page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
 	}
 
-	/* Fallback allocation of normal pages */
-	if (!page)
-		page = alloc_pages_node(node, gfp, align);
 	return page;
 }
 
@@ -258,6 +254,7 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
  * dma_free_contiguous() - release allocated pages
  * @dev:   Pointer to device for which the pages were allocated.
  * @page:  Pointer to the allocated pages.
+	int node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
  * @size:  Size of allocated pages.
  *
  * This function releases memory allocated by dma_alloc_contiguous(). As the
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 795c9b095d75..d82d184463ce 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -85,6 +85,8 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
 struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
+	size_t alloc_size = PAGE_ALIGN(size);
+	int node = dev_to_node(dev);
 	struct page *page = NULL;
 	u64 phys_mask;
 
@@ -95,8 +97,11 @@ struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
 	gfp &= ~__GFP_ZERO;
 	gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
 			&phys_mask);
+	page = dma_alloc_contiguous(dev, alloc_size, gfp);
+	if (page && dma_coherent_ok(dev, page_to_phys(page), size))
+		return page;
 again:
-	page = dma_alloc_contiguous(dev, size, gfp);
+	page = alloc_pages_node(node, gfp, get_order(alloc_size));
 	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
 		dma_free_contiguous(dev, page, size);
 		page = NULL;
-- 
2.20.1

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16 16:08 Tobias Klausmann
2019-08-16 16:43 ` Christoph Hellwig
2019-08-16 20:16   ` Tobias Klausmann
2019-08-16 22:25     ` Nicolin Chen
2019-08-16 22:42       ` Tobias Klausmann
2019-08-18  3:13       ` Hillf Danton
2019-08-18 22:38         ` Tobias Klausmann
2019-08-20  1:58           ` Nicolin Chen
2019-08-20  2:14             ` Christoph Hellwig
2019-08-20  3:05           ` Christoph Hellwig [this message]
2019-08-20  6:58           ` Hillf Danton
2019-08-20  7:12             ` Christoph Hellwig
2019-08-20 20:24               ` Tobias Klausmann
2019-08-20  2:29 Hillf Danton

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190820030514.GA24612@lst.de \
    --to=hch@lst.de \
    --cc=ath10k@lists.infradead.org \
    --cc=davem@davemloft.net \
    --cc=hdanton@sina.com \
    --cc=iommu@lists.linux-foundation.org \
    --cc=kvalo@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=nicoleotsuka@gmail.com \
    --cc=robin.murphy@arm.com \
    --cc=tobias.johannes.klausmann@mni.thm.de \
    --cc=tobias.klausmann@freenet.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

IOMMU Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-iommu/0 linux-iommu/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-iommu linux-iommu/ https://lore.kernel.org/linux-iommu \
		iommu@lists.linux-foundation.org iommu@archiver.kernel.org
	public-inbox-index linux-iommu

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.linux-foundation.lists.iommu


AGPL code for this site: git clone https://public-inbox.org/ public-inbox