From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>,
Dan Williams <dan.j.williams@intel.com>
Cc: "Felix Kuehling" <Felix.Kuehling@amd.com>,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"Pan, Xinhui" <Xinhui.Pan@amd.com>,
"Ben Skeggs" <bskeggs@redhat.com>,
"Karol Herbst" <kherbst@redhat.com>,
"Lyude Paul" <lyude@redhat.com>, "Jason Gunthorpe" <jgg@ziepe.ca>,
"Alistair Popple" <apopple@nvidia.com>,
"Logan Gunthorpe" <logang@deltatee.com>,
"Ralph Campbell" <rcampbell@nvidia.com>,
linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org,
nvdimm@lists.linux.dev, linux-mm@kvack.org,
"Jason Gunthorpe" <jgg@nvidia.com>,
"Chaitanya Kulkarni" <kch@nvidia.com>
Subject: [PATCH 05/27] mm: simplify freeing of devmap managed pages
Date: Thu, 10 Feb 2022 08:28:06 +0100 [thread overview]
Message-ID: <20220210072828.2930359-6-hch@lst.de> (raw)
In-Reply-To: <20220210072828.2930359-1-hch@lst.de>
Make put_devmap_managed_page return if it took charge of the page
or not and remove the separate page_is_devmap_managed helper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
---
include/linux/mm.h | 34 ++++++++++------------------------
mm/memremap.c | 20 +++++++++-----------
mm/swap.c | 10 +---------
3 files changed, 20 insertions(+), 44 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 91dd0bc786a9ec..26baadcef4556b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1094,33 +1094,24 @@ static inline bool is_zone_movable_page(const struct page *page)
#ifdef CONFIG_DEV_PAGEMAP_OPS
DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
-static inline bool page_is_devmap_managed(struct page *page)
+bool __put_devmap_managed_page(struct page *page);
+static inline bool put_devmap_managed_page(struct page *page)
{
if (!static_branch_unlikely(&devmap_managed_key))
return false;
if (!is_zone_device_page(page))
return false;
- switch (page->pgmap->type) {
- case MEMORY_DEVICE_PRIVATE:
- case MEMORY_DEVICE_FS_DAX:
- return true;
- default:
- break;
- }
- return false;
+ if (page->pgmap->type != MEMORY_DEVICE_PRIVATE &&
+ page->pgmap->type != MEMORY_DEVICE_FS_DAX)
+ return false;
+ return __put_devmap_managed_page(page);
}
-void put_devmap_managed_page(struct page *page);
-
#else /* CONFIG_DEV_PAGEMAP_OPS */
-static inline bool page_is_devmap_managed(struct page *page)
+static inline bool put_devmap_managed_page(struct page *page)
{
return false;
}
-
-static inline void put_devmap_managed_page(struct page *page)
-{
-}
#endif /* CONFIG_DEV_PAGEMAP_OPS */
static inline bool is_device_private_page(const struct page *page)
@@ -1220,16 +1211,11 @@ static inline void put_page(struct page *page)
struct folio *folio = page_folio(page);
/*
- * For devmap managed pages we need to catch refcount transition from
- * 2 to 1, when refcount reach one it means the page is free and we
- * need to inform the device driver through callback. See
- * include/linux/memremap.h and HMM for details.
+ * For some devmap managed pages we need to catch refcount transition
+ * from 2 to 1:
*/
- if (page_is_devmap_managed(&folio->page)) {
- put_devmap_managed_page(&folio->page);
+ if (put_devmap_managed_page(&folio->page))
return;
- }
-
folio_put(folio);
}
diff --git a/mm/memremap.c b/mm/memremap.c
index 55d23e9f5c04ec..f41233a67edb12 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -502,24 +502,22 @@ void free_devmap_managed_page(struct page *page)
page->pgmap->ops->page_free(page);
}
-void put_devmap_managed_page(struct page *page)
+bool __put_devmap_managed_page(struct page *page)
{
- int count;
-
- if (WARN_ON_ONCE(!page_is_devmap_managed(page)))
- return;
-
- count = page_ref_dec_return(page);
-
/*
* devmap page refcounts are 1-based, rather than 0-based: if
* refcount is 1, then the page is free and the refcount is
* stable because nobody holds a reference on the page.
*/
- if (count == 1)
+ switch (page_ref_dec_return(page)) {
+ case 1:
free_devmap_managed_page(page);
- else if (!count)
+ break;
+ case 0:
__put_page(page);
+ break;
+ }
+ return true;
}
-EXPORT_SYMBOL(put_devmap_managed_page);
+EXPORT_SYMBOL(__put_devmap_managed_page);
#endif /* CONFIG_DEV_PAGEMAP_OPS */
diff --git a/mm/swap.c b/mm/swap.c
index 08058f74cae23e..25b55c56614311 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -930,16 +930,8 @@ void release_pages(struct page **pages, int nr)
unlock_page_lruvec_irqrestore(lruvec, flags);
lruvec = NULL;
}
- /*
- * ZONE_DEVICE pages that return 'false' from
- * page_is_devmap_managed() do not require special
- * processing, and instead, expect a call to
- * put_page_testzero().
- */
- if (page_is_devmap_managed(page)) {
- put_devmap_managed_page(page);
+ if (put_devmap_managed_page(page))
continue;
- }
if (put_page_testzero(page))
put_dev_pagemap(page->pgmap);
continue;
--
2.30.2
next prev parent reply other threads:[~2022-02-10 7:29 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-10 7:28 start sorting out the ZONE_DEVICE refcount mess v2 Christoph Hellwig
2022-02-10 7:28 ` [PATCH 01/27] mm: remove a pointless CONFIG_ZONE_DEVICE check in memremap_pages Christoph Hellwig
2022-02-10 11:37 ` Miaohe Lin
2022-02-10 7:28 ` [PATCH 02/27] mm: remove the __KERNEL__ guard from <linux/mm.h> Christoph Hellwig
2022-02-10 7:28 ` [PATCH 03/27] mm: remove pointless includes from <linux/hmm.h> Christoph Hellwig
2022-02-10 9:39 ` Muchun Song
2022-02-10 7:28 ` [PATCH 04/27] mm: move free_devmap_managed_page to memremap.c Christoph Hellwig
2022-02-10 7:28 ` Christoph Hellwig [this message]
2022-02-10 7:28 ` [PATCH 06/27] mm: don't include <linux/memremap.h> in <linux/mm.h> Christoph Hellwig
2022-02-10 7:28 ` [PATCH 07/27] mm: remove the extra ZONE_DEVICE struct page refcount Christoph Hellwig
2022-02-10 7:28 ` [PATCH 08/27] fsdax: depend on ZONE_DEVICE || FS_DAX_LIMITED Christoph Hellwig
2022-02-10 7:28 ` [PATCH 09/27] mm: generalize the pgmap based page_free infrastructure Christoph Hellwig
2022-02-14 17:37 ` Logan Gunthorpe
2022-02-10 7:28 ` [PATCH 10/27] mm: refactor check_and_migrate_movable_pages Christoph Hellwig
2022-02-10 7:28 ` [PATCH 11/27] mm: refactor the ZONE_DEVICE handling in migrate_vma_insert_page Christoph Hellwig
2022-02-10 10:48 ` Alistair Popple
2022-02-10 7:28 ` [PATCH 12/27] mm: refactor the ZONE_DEVICE handling in migrate_vma_pages Christoph Hellwig
2022-02-10 10:46 ` Alistair Popple
2022-02-10 7:28 ` [PATCH 13/27] mm: move the migrate_vma_* device migration code into it's own file Christoph Hellwig
2022-02-10 10:35 ` Alistair Popple
2022-02-10 15:23 ` Christoph Hellwig
2022-02-10 7:28 ` [PATCH 14/27] mm: build migrate_vma_* for all configs with ZONE_DEVICE support Christoph Hellwig
2022-02-10 10:43 ` Alistair Popple
2022-02-10 7:28 ` [PATCH 15/27] mm: add zone device coherent type memory support Christoph Hellwig
2022-02-10 7:28 ` [PATCH 16/27] mm: add device coherent vma selection for memory migration Christoph Hellwig
2022-02-10 7:28 ` [PATCH 17/27] mm/gup: fail get_user_pages for LONGTERM dev coherent type Christoph Hellwig
2022-02-10 7:28 ` [PATCH 18/27] drm/amdkfd: add SPM support for SVM Christoph Hellwig
2022-02-10 7:28 ` [PATCH 19/27] drm/amdkfd: coherent type as sys mem on migration to ram Christoph Hellwig
2022-02-10 7:28 ` [PATCH 20/27] lib: test_hmm add ioctl to get zone device type Christoph Hellwig
2022-02-10 7:28 ` [PATCH 21/27] lib: test_hmm add module param for " Christoph Hellwig
2022-02-10 7:28 ` [PATCH 22/27] lib: add support for device coherent type in test_hmm Christoph Hellwig
2022-02-10 7:28 ` [PATCH 23/27] tools: update hmm-test to support device coherent type Christoph Hellwig
2022-02-10 7:28 ` [PATCH 24/27] tools: update test_hmm script to support SP config Christoph Hellwig
2022-02-10 7:28 ` [PATCH 25/27] mm: remove the vma check in migrate_vma_setup() Christoph Hellwig
2022-02-10 7:28 ` [PATCH 26/27] mm/gup: migrate device coherent pages when pinning instead of failing Christoph Hellwig
2022-02-10 7:28 ` [PATCH 27/27] tools: add hmm gup test for long term pinned device pages Christoph Hellwig
2022-02-10 10:56 ` start sorting out the ZONE_DEVICE refcount mess v2 Alistair Popple
2022-02-10 17:36 ` Sierra Guiza, Alejandro (Alex)
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