linux-xfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alex Sierra <alex.sierra@amd.com>
To: akpm@linux-foundation.org, Felix.Kuehling@amd.com,
	linux-mm@kvack.org, rcampbell@nvidia.com,
	linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org
Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	hch@lst.de, jgg@nvidia.com, jglisse@redhat.com
Subject: [PATCH v1 01/14] ext4/xfs: add page refcount helper
Date: Tue, 24 Aug 2021 22:48:15 -0500	[thread overview]
Message-ID: <20210825034828.12927-2-alex.sierra@amd.com> (raw)
In-Reply-To: <20210825034828.12927-1-alex.sierra@amd.com>

From: Ralph Campbell <rcampbell@nvidia.com>

There are several places where ZONE_DEVICE struct pages assume a reference
count == 1 means the page is idle and free. Instead of open coding this,
add a helper function to hide this detail.

Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
v3:
[AS]: rename dax_layout_is_idle_page func to dax_page_unused

v4:
[AS]: This ref count functionality was missing on fuse/dax.c.
---
 fs/dax.c            |  4 ++--
 fs/ext4/inode.c     |  5 +----
 fs/fuse/dax.c       |  4 +---
 fs/xfs/xfs_file.c   |  4 +---
 include/linux/dax.h | 10 ++++++++++
 5 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 62352cbcf0f4..c387d09e3e5a 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -369,7 +369,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping,
 	for_each_mapped_pfn(entry, pfn) {
 		struct page *page = pfn_to_page(pfn);
 
-		WARN_ON_ONCE(trunc && page_ref_count(page) > 1);
+		WARN_ON_ONCE(trunc && !dax_page_unused(page));
 		WARN_ON_ONCE(page->mapping && page->mapping != mapping);
 		page->mapping = NULL;
 		page->index = 0;
@@ -383,7 +383,7 @@ static struct page *dax_busy_page(void *entry)
 	for_each_mapped_pfn(entry, pfn) {
 		struct page *page = pfn_to_page(pfn);
 
-		if (page_ref_count(page) > 1)
+		if (!dax_page_unused(page))
 			return page;
 	}
 	return NULL;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index fe6045a46599..05ffe6875cb1 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3971,10 +3971,7 @@ int ext4_break_layouts(struct inode *inode)
 		if (!page)
 			return 0;
 
-		error = ___wait_var_event(&page->_refcount,
-				atomic_read(&page->_refcount) == 1,
-				TASK_INTERRUPTIBLE, 0, 0,
-				ext4_wait_dax_page(ei));
+		error = dax_wait_page(ei, page, ext4_wait_dax_page);
 	} while (error == 0);
 
 	return error;
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index ff99ab2a3c43..2b1f190ba78a 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -677,9 +677,7 @@ static int __fuse_dax_break_layouts(struct inode *inode, bool *retry,
 		return 0;
 
 	*retry = true;
-	return ___wait_var_event(&page->_refcount,
-			atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
-			0, 0, fuse_wait_dax_page(inode));
+	return dax_wait_page(inode, page, fuse_wait_dax_page);
 }
 
 /* dmap_end == 0 leads to unmapping of whole file */
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 396ef36dcd0a..182057281086 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -840,9 +840,7 @@ xfs_break_dax_layouts(
 		return 0;
 
 	*retry = true;
-	return ___wait_var_event(&page->_refcount,
-			atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
-			0, 0, xfs_wait_dax_page(inode));
+	return dax_wait_page(inode, page, xfs_wait_dax_page);
 }
 
 int
diff --git a/include/linux/dax.h b/include/linux/dax.h
index b52f084aa643..8b5da1d60dbc 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -243,6 +243,16 @@ static inline bool dax_mapping(struct address_space *mapping)
 	return mapping->host && IS_DAX(mapping->host);
 }
 
+static inline bool dax_page_unused(struct page *page)
+{
+	return page_ref_count(page) == 1;
+}
+
+#define dax_wait_page(_inode, _page, _wait_cb)				\
+	___wait_var_event(&(_page)->_refcount,				\
+		dax_page_unused(_page),				\
+		TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode))
+
 #ifdef CONFIG_DEV_DAX_HMEM_DEVICES
 void hmem_register_device(int target_nid, struct resource *r);
 #else
-- 
2.32.0


  reply	other threads:[~2021-08-25  3:49 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-25  3:48 [PATCH v1 00/14] Add MEMORY_DEVICE_PUBLIC for CPU-accessible coherent device memory Alex Sierra
2021-08-25  3:48 ` Alex Sierra [this message]
2021-08-25  7:35   ` [PATCH v1 01/14] ext4/xfs: add page refcount helper Christoph Hellwig
2021-08-25 15:09   ` Theodore Ts'o
2021-08-25 15:49   ` Darrick J. Wong
2021-08-25  3:48 ` [PATCH v1 02/14] mm: remove extra ZONE_DEVICE struct page refcount Alex Sierra
2021-08-25  7:35   ` Christoph Hellwig
2021-08-25 11:15   ` Vlastimil Babka
2021-08-25 17:49     ` Ralph Campbell
2021-08-27 11:26       ` Vlastimil Babka
2021-08-25  3:48 ` [PATCH v1 03/14] mm: add iomem vma selection for memory migration Alex Sierra
2021-08-25  7:40   ` Christoph Hellwig
2021-08-25  7:46   ` Christoph Hellwig
2021-08-25 18:24     ` Sierra Guiza, Alejandro (Alex)
2021-08-26 22:27       ` Felix Kuehling
2021-08-30  8:28         ` Christoph Hellwig
2021-08-30 17:04           ` Felix Kuehling
2021-09-01  8:29             ` Christoph Hellwig
2021-09-01 15:40               ` Felix Kuehling
2021-09-01 22:03                 ` Dave Chinner
2021-09-01 23:07                   ` Felix Kuehling
2021-09-02  1:14                     ` Dave Chinner
2021-09-09  4:55                       ` Felix Kuehling
2021-09-02  8:18                 ` Christoph Hellwig
2021-09-02 18:07                   ` Dan Williams
2021-09-09  4:02                   ` Felix Kuehling
2021-08-25 14:24   ` Felix Kuehling
2021-08-25  3:48 ` [PATCH v1 04/14] mm: add zone device public type memory support Alex Sierra
2021-08-25  3:48 ` [PATCH v1 05/14] drm/amdkfd: ref count init for device pages Alex Sierra
2021-08-25 14:34   ` Felix Kuehling
2021-08-25  3:48 ` [PATCH v1 06/14] drm/amdkfd: add SPM support for SVM Alex Sierra
2021-08-25 14:45   ` Felix Kuehling
2021-08-25  3:48 ` [PATCH v1 07/14] drm/amdkfd: public type as sys mem on migration to ram Alex Sierra
2021-08-25  3:48 ` [PATCH v1 08/14] mm: add public type support to migrate_vma helpers Alex Sierra
2021-08-25  7:47   ` Christoph Hellwig
2021-08-25  3:48 ` [PATCH v1 09/14] mm: call pgmap->ops->page_free for DEVICE_PUBLIC pages Alex Sierra
2021-08-25  7:46   ` Christoph Hellwig
2021-08-25  3:48 ` [PATCH v1 10/14] lib: test_hmm add ioctl to get zone device type Alex Sierra
2021-08-25  3:48 ` [PATCH v1 11/14] lib: test_hmm add module param for " Alex Sierra
2021-08-25  3:48 ` [PATCH v1 12/14] lib: add support for device public type in test_hmm Alex Sierra
2021-08-25  3:48 ` [PATCH v1 13/14] tools: update hmm-test to support device public type Alex Sierra
2021-08-25  3:48 ` [PATCH v1 14/14] tools: update test_hmm script to support SP config Alex Sierra

Reply instructions:

You may reply publicly 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=20210825034828.12927-2-alex.sierra@amd.com \
    --to=alex.sierra@amd.com \
    --cc=Felix.Kuehling@amd.com \
    --cc=akpm@linux-foundation.org \
    --cc=amd-gfx@lists.freedesktop.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=hch@lst.de \
    --cc=jgg@nvidia.com \
    --cc=jglisse@redhat.com \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-xfs@vger.kernel.org \
    --cc=rcampbell@nvidia.com \
    --subject='Re: [PATCH v1 01/14] ext4/xfs: add page refcount helper' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).