| Message ID | 20210715033704.692967-23-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Memory folios | expand |
On Thu, Jul 15, 2021 at 04:35:08AM +0100, Matthew Wilcox (Oracle) wrote: > 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> > --- > include/linux/pagemap.h | 11 +++++++---- > mm/filemap.c | 20 +++++++++----------- > mm/memory.c | 8 ++++---- > 3 files changed, 20 insertions(+), 19 deletions(-) Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Matthew Wilcox (Oracle) <willy@infradead.org> wrote: > 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> Reviewed-by: David Howells <dhowells@redhat.com>
On 7/15/21 5:35 AM, Matthew Wilcox (Oracle) wrote: > 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: Vlastimil Babka <vbabka@suse.cz> Nit: > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -1625,48 +1625,46 @@ 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 s/1/true/ ? :) > - * with the page locked and the mmap_lock unperturbed. > + * 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; > } > > /**
On Tue, Aug 10, 2021 at 06:08:03PM +0200, Vlastimil Babka wrote: > > * If neither ALLOW_RETRY nor KILLABLE are set, will always return 1 > > s/1/true/ ? :) Fixed; thanks.
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 03fea8bbfd8e..626dbccbfb90 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -655,7 +655,7 @@ 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); @@ -716,13 +716,16 @@ 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); } /* diff --git a/mm/filemap.c b/mm/filemap.c index 04fb4a84cf0d..fb6398a532e5 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1625,48 +1625,46 @@ 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. + * 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; } /** diff --git a/mm/memory.c b/mm/memory.c index 747a01d495f2..2f111f9b3dbc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4248,7 +4248,7 @@ 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()). */ @@ -4489,7 +4489,7 @@ 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) { @@ -4593,7 +4593,7 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf) * 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) @@ -4749,7 +4749,7 @@ 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)