| Message ID | 20201009195033.3208459-34-ira.weiny@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | PMEM: Introduce stray write protection for PMEM | expand |
On Fri, 9 Oct 2020, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > The kmap() calls in this FS are localized to a single thread. To avoid > the over head of global PKRS updates use the new kmap_thread() call. > > Cc: Nicolas Pitre <nico@fluxnic.net> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> Acked-by: Nicolas Pitre <nico@fluxnic.net> > fs/cramfs/inode.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c > index 912308600d39..003c014a42ed 100644 > --- a/fs/cramfs/inode.c > +++ b/fs/cramfs/inode.c > @@ -247,8 +247,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, > struct page *page = pages[i]; > > if (page) { > - memcpy(data, kmap(page), PAGE_SIZE); > - kunmap(page); > + memcpy(data, kmap_thread(page), PAGE_SIZE); > + kunmap_thread(page); > put_page(page); > } else > memset(data, 0, PAGE_SIZE); > @@ -826,7 +826,7 @@ static int cramfs_readpage(struct file *file, struct page *page) > > maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; > bytes_filled = 0; > - pgdata = kmap(page); > + pgdata = kmap_thread(page); > > if (page->index < maxblock) { > struct super_block *sb = inode->i_sb; > @@ -914,13 +914,13 @@ static int cramfs_readpage(struct file *file, struct page *page) > > memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); > flush_dcache_page(page); > - kunmap(page); > + kunmap_thread(page); > SetPageUptodate(page); > unlock_page(page); > return 0; > > err: > - kunmap(page); > + kunmap_thread(page); > ClearPageUptodate(page); > SetPageError(page); > unlock_page(page); > -- > 2.28.0.rc0.12.gb6a658bd00c9 > >
On Tue, Oct 13, 2020 at 11:44:29AM -0700, Dan Williams wrote: > On Fri, Oct 9, 2020 at 12:52 PM <ira.weiny@intel.com> wrote: > > > > From: Ira Weiny <ira.weiny@intel.com> > > > > The kmap() calls in this FS are localized to a single thread. To avoid > > the over head of global PKRS updates use the new kmap_thread() call. > > > > Cc: Nicolas Pitre <nico@fluxnic.net> > > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > > fs/cramfs/inode.c | 10 +++++----- > > 1 file changed, 5 insertions(+), 5 deletions(-) > > > > diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c > > index 912308600d39..003c014a42ed 100644 > > --- a/fs/cramfs/inode.c > > +++ b/fs/cramfs/inode.c > > @@ -247,8 +247,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, > > struct page *page = pages[i]; > > > > if (page) { > > - memcpy(data, kmap(page), PAGE_SIZE); > > - kunmap(page); > > + memcpy(data, kmap_thread(page), PAGE_SIZE); > > + kunmap_thread(page); > > Why does this need a sleepable kmap? This looks like a textbook > kmap_atomic() use case. There's a lot of code of this form. Could we perhaps have: static inline void copy_to_highpage(struct page *to, void *vfrom, unsigned int size) { char *vto = kmap_atomic(to); memcpy(vto, vfrom, size); kunmap_atomic(vto); } in linux/highmem.h ?
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index 912308600d39..003c014a42ed 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -247,8 +247,8 @@ static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset, struct page *page = pages[i]; if (page) { - memcpy(data, kmap(page), PAGE_SIZE); - kunmap(page); + memcpy(data, kmap_thread(page), PAGE_SIZE); + kunmap_thread(page); put_page(page); } else memset(data, 0, PAGE_SIZE); @@ -826,7 +826,7 @@ static int cramfs_readpage(struct file *file, struct page *page) maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT; bytes_filled = 0; - pgdata = kmap(page); + pgdata = kmap_thread(page); if (page->index < maxblock) { struct super_block *sb = inode->i_sb; @@ -914,13 +914,13 @@ static int cramfs_readpage(struct file *file, struct page *page) memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled); flush_dcache_page(page); - kunmap(page); + kunmap_thread(page); SetPageUptodate(page); unlock_page(page); return 0; err: - kunmap(page); + kunmap_thread(page); ClearPageUptodate(page); SetPageError(page); unlock_page(page);