| Message ID | 1458499278-1516-14-git-send-email-kirill.shutemov@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Mar 20, 2016 at 09:40:20PM +0300, Kirill A. Shutemov wrote: > PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago > with promise that one day it will be possible to implement page cache with > bigger chunks than PAGE_SIZE. > > This promise never materialized. And unlikely will. > > We have many places where PAGE_CACHE_SIZE assumed to be equal to > PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* > or PAGE_* constant should be used in a particular case, especially on the > border between fs and mm. > > Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much > breakage to be doable. > > Let's stop pretending that pages in page cache are special. They are not. > > The changes are pretty straight-forward: > > - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; > > - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; > > - page_cache_get() -> get_page(); > > - page_cache_release() -> put_page(); > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Vishal Verma <vishal.l.verma@intel.com> > Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Sure, this seems right. Thanks for making this simpler. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> > --- > drivers/nvdimm/btt.c | 2 +- > drivers/nvdimm/pmem.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c > index c32cbb593600..f068b6513cd2 100644 > --- a/drivers/nvdimm/btt.c > +++ b/drivers/nvdimm/btt.c > @@ -1204,7 +1204,7 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector, > { > struct btt *btt = bdev->bd_disk->private_data; > > - btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector); > + btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, rw, sector); > page_endio(page, rw & WRITE, 0); > return 0; > } > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index ca5721c306bb..a1a29c711532 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -151,7 +151,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, > struct pmem_device *pmem = bdev->bd_disk->private_data; > int rc; > > - rc = pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector); > + rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector); > if (rw & WRITE) > wmb_pmem(); > > -- > 2.7.0 > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index c32cbb593600..f068b6513cd2 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1204,7 +1204,7 @@ static int btt_rw_page(struct block_device *bdev, sector_t sector, { struct btt *btt = bdev->bd_disk->private_data; - btt_do_bvec(btt, NULL, page, PAGE_CACHE_SIZE, 0, rw, sector); + btt_do_bvec(btt, NULL, page, PAGE_SIZE, 0, rw, sector); page_endio(page, rw & WRITE, 0); return 0; } diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index ca5721c306bb..a1a29c711532 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -151,7 +151,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector, struct pmem_device *pmem = bdev->bd_disk->private_data; int rc; - rc = pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector); + rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector); if (rw & WRITE) wmb_pmem();
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> --- drivers/nvdimm/btt.c | 2 +- drivers/nvdimm/pmem.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)