mm/filemap: Add __folio_lock_or_retry()

Convert __lock_page_or_retry() to __folio_lock_or_retry().  This actually
saves 4 bytes in the only caller of lock_page_or_retry() (due to better
register allocation) and saves the 14 byte cost of calling page_folio()
in __folio_lock_or_retry() for a total saving of 18 bytes.  Also use
a bool for the return type.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
This commit is contained in:
Matthew Wilcox (Oracle) 2021-03-18 21:39:45 -04:00
parent 6baa8d602e
commit 9138e47ed4
3 changed files with 21 additions and 20 deletions

View File

@ -654,7 +654,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page,
void __folio_lock(struct folio *folio);
int __folio_lock_killable(struct folio *folio);
extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
unsigned int flags);
void unlock_page(struct page *page);
void folio_unlock(struct folio *folio);
@ -715,13 +715,16 @@ static inline int lock_page_killable(struct page *page)
* caller indicated that it can handle a retry.
*
* Return value and mmap_lock implications depend on flags; see
* __lock_page_or_retry().
* __folio_lock_or_retry().
*/
static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
static inline bool lock_page_or_retry(struct page *page, struct mm_struct *mm,
unsigned int flags)
{
struct folio *folio;
might_sleep();
return trylock_page(page) || __lock_page_or_retry(page, mm, flags);
folio = page_folio(page);
return folio_trylock(folio) || __folio_lock_or_retry(folio, mm, flags);
}
/*

View File

@ -1680,48 +1680,46 @@ static int __folio_lock_async(struct folio *folio, struct wait_page_queue *wait)
/*
* Return values:
* 1 - page is locked; mmap_lock is still held.
* 0 - page is not locked.
* true - folio is locked; mmap_lock is still held.
* false - folio is not locked.
* mmap_lock has been released (mmap_read_unlock(), unless flags had both
* FAULT_FLAG_ALLOW_RETRY and FAULT_FLAG_RETRY_NOWAIT set, in
* which case mmap_lock is still held.
*
* If neither ALLOW_RETRY nor KILLABLE are set, will always return 1
* with the page locked and the mmap_lock unperturbed.
* If neither ALLOW_RETRY nor KILLABLE are set, will always return true
* with the folio locked and the mmap_lock unperturbed.
*/
int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
unsigned int flags)
{
struct folio *folio = page_folio(page);
if (fault_flag_allow_retry_first(flags)) {
/*
* CAUTION! In this case, mmap_lock is not released
* even though return 0.
*/
if (flags & FAULT_FLAG_RETRY_NOWAIT)
return 0;
return false;
mmap_read_unlock(mm);
if (flags & FAULT_FLAG_KILLABLE)
folio_wait_locked_killable(folio);
else
folio_wait_locked(folio);
return 0;
return false;
}
if (flags & FAULT_FLAG_KILLABLE) {
int ret;
bool ret;
ret = __folio_lock_killable(folio);
if (ret) {
mmap_read_unlock(mm);
return 0;
return false;
}
} else {
__folio_lock(folio);
}
return 1;
return true;
}
/**

View File

@ -4258,7 +4258,7 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf)
* We enter with non-exclusive mmap_lock (to exclude vma changes,
* but allow concurrent faults).
* The mmap_lock may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
* return value. See filemap_fault() and __folio_lock_or_retry().
* If mmap_lock is released, vma may become invalid (for example
* by other thread calling munmap()).
*/
@ -4499,7 +4499,7 @@ static vm_fault_t wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
* concurrent faults).
*
* The mmap_lock may have been released depending on flags and our return value.
* See filemap_fault() and __lock_page_or_retry().
* See filemap_fault() and __folio_lock_or_retry().
*/
static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
{
@ -4603,7 +4603,7 @@ unlock:
* By the time we get here, we already hold the mm semaphore
*
* The mmap_lock may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
* return value. See filemap_fault() and __folio_lock_or_retry().
*/
static vm_fault_t __handle_mm_fault(struct vm_area_struct *vma,
unsigned long address, unsigned int flags)
@ -4759,7 +4759,7 @@ static inline void mm_account_fault(struct pt_regs *regs,
* By the time we get here, we already hold the mm semaphore
*
* The mmap_lock may have been released depending on flags and our
* return value. See filemap_fault() and __lock_page_or_retry().
* return value. See filemap_fault() and __folio_lock_or_retry().
*/
vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
unsigned int flags, struct pt_regs *regs)