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mm: remove page_mkclean()

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There are no more users of page_mkclean(), remove it and update the
document and comment.

Link: https://lkml.kernel.org/r/20240604114822.2089819-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Kefeng Wang 2024-06-04 19:48:22 +08:00 committed by Andrew Morton
parent 645b1399fa
commit a929e0d10f
6 changed files with 9 additions and 13 deletions
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8
Documentation/core-api/pin_user_pages.rst
View File

@ -132,7 +132,7 @@ CASE 1: Direct IO (DIO)
-----------------------
There are GUP references to pages that are serving
as DIO buffers. These buffers are needed for a relatively short time (so they
are not "long term"). No special synchronization with page_mkclean() or
are not "long term"). No special synchronization with folio_mkclean() or
munmap() is provided. Therefore, flags to set at the call site are: ::
FOLL_PIN
@ -144,7 +144,7 @@ CASE 2: RDMA
------------
There are GUP references to pages that are serving as DMA
buffers. These buffers are needed for a long time ("long term"). No special
synchronization with page_mkclean() or munmap() is provided. Therefore, flags
synchronization with folio_mkclean() or munmap() is provided. Therefore, flags
to set at the call site are: ::
FOLL_PIN | FOLL_LONGTERM
@ -170,7 +170,7 @@ callback, simply remove the range from the device's page tables.
Either way, as long as the driver unpins the pages upon mmu notifier callback,
then there is proper synchronization with both filesystem and mm
(page_mkclean(), munmap(), etc). Therefore, neither flag needs to be set.
(folio_mkclean(), munmap(), etc). Therefore, neither flag needs to be set.
CASE 4: Pinning for struct page manipulation only
-------------------------------------------------
@ -200,7 +200,7 @@ folio_maybe_dma_pinned(): the whole point of pinning
====================================================
The whole point of marking folios as "DMA-pinned" or "gup-pinned" is to be able
to query, "is this folio DMA-pinned?" That allows code such as page_mkclean()
to query, "is this folio DMA-pinned?" That allows code such as folio_mkclean()
(and file system writeback code in general) to make informed decisions about
what to do when a folio cannot be unmapped due to such pins.

4
drivers/video/fbdev/core/fb_defio.c
View File

@ -113,7 +113,7 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf)
printk(KERN_ERR "no mapping available\n");
BUG_ON(!page->mapping);
page->index = vmf->pgoff; /* for page_mkclean() */
page->index = vmf->pgoff; /* for folio_mkclean() */
vmf->page = page;
return 0;
@ -161,7 +161,7 @@ static vm_fault_t fb_deferred_io_track_page(struct fb_info *info, unsigned long
/*
* We want the page to remain locked from ->page_mkwrite until
* the PTE is marked dirty to avoid page_mkclean() being called
* the PTE is marked dirty to avoid folio_mkclean() being called
* before the PTE is updated, which would leave the page ignored
* by defio.
* Do this by locking the page here and informing the caller

2
include/linux/mm.h
View File

@ -1577,7 +1577,7 @@ static inline void put_page(struct page *page)
* issue.
*
* Locking: the lockless algorithm described in folio_try_get_rcu()
* provides safe operation for get_user_pages(), page_mkclean() and
* provides safe operation for get_user_pages(), folio_mkclean() and
* other calls that race to set up page table entries.
*/
#define GUP_PIN_COUNTING_BIAS (1U << 10)

4
include/linux/rmap.h
View File

@ -802,8 +802,4 @@ static inline int folio_mkclean(struct folio *folio)
}
#endif /* CONFIG_MMU */
static inline int page_mkclean(struct page *page)
{
return folio_mkclean(page_folio(page));
}
#endif /* _LINUX_RMAP_H */

2
mm/gup.c
View File

@ -378,7 +378,7 @@ void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
* 1) This code sees the page as already dirty, so it
* skips the call to set_page_dirty(). That could happen
* because clear_page_dirty_for_io() called
* page_mkclean(), followed by set_page_dirty().
* folio_mkclean(), followed by set_page_dirty().
* However, now the page is going to get written back,
* which meets the original intention of setting it
* dirty, so all is well: clear_page_dirty_for_io() goes

2
mm/mremap.c
View File

@ -198,7 +198,7 @@ static int move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
* PTE.
*
* NOTE! Both old and new PTL matter: the old one
* for racing with page_mkclean(), the new one to
* for racing with folio_mkclean(), the new one to
* make sure the physical page stays valid until
* the TLB entry for the old mapping has been
* flushed.