Return-Path: linux-nfs-owner@vger.kernel.org Received: from cantor2.suse.de ([195.135.220.15]:56986 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014AbbANMsB (ORCPT ); Wed, 14 Jan 2015 07:48:01 -0500 Date: Wed, 14 Jan 2015 13:47:55 +0100 From: Jan Kara To: Christoph Hellwig Cc: Jens Axboe , David Howells , Tejun Heo , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org Subject: Re: [PATCH 02/12] fs: kill BDI_CAP_SWAP_BACKED Message-ID: <20150114124755.GE10215@quack.suse.cz> References: <1421228561-16857-1-git-send-email-hch@lst.de> <1421228561-16857-3-git-send-email-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1421228561-16857-3-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed 14-01-15 10:42:31, Christoph Hellwig wrote: > This bdi flag isn't too useful - we can determine that a vma is backed by > either swap or shmem trivially in the caller. > > This also allows removing the backing_dev_info instaces for swap and shmem > in favor of noop_backing_dev_info. > > Signed-off-by: Christoph Hellwig > Reviewed-by: Tejun Heo Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > include/linux/backing-dev.h | 13 ------------- > mm/madvise.c | 17 ++++++++++------- > mm/shmem.c | 25 +++++++------------------ > mm/swap.c | 2 -- > mm/swap_state.c | 7 +------ > 5 files changed, 18 insertions(+), 46 deletions(-) > > diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h > index 5da6012..e936cea 100644 > --- a/include/linux/backing-dev.h > +++ b/include/linux/backing-dev.h > @@ -238,8 +238,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); > * BDI_CAP_WRITE_MAP: Can be mapped for writing > * BDI_CAP_EXEC_MAP: Can be mapped for execution > * > - * BDI_CAP_SWAP_BACKED: Count shmem/tmpfs objects as swap-backed. > - * > * BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold. > */ > #define BDI_CAP_NO_ACCT_DIRTY 0x00000001 > @@ -250,7 +248,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); > #define BDI_CAP_WRITE_MAP 0x00000020 > #define BDI_CAP_EXEC_MAP 0x00000040 > #define BDI_CAP_NO_ACCT_WB 0x00000080 > -#define BDI_CAP_SWAP_BACKED 0x00000100 > #define BDI_CAP_STABLE_WRITES 0x00000200 > #define BDI_CAP_STRICTLIMIT 0x00000400 > > @@ -329,11 +326,6 @@ static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) > BDI_CAP_NO_WRITEBACK)); > } > > -static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi) > -{ > - return bdi->capabilities & BDI_CAP_SWAP_BACKED; > -} > - > static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) > { > return bdi_cap_writeback_dirty(mapping->backing_dev_info); > @@ -344,11 +336,6 @@ static inline bool mapping_cap_account_dirty(struct address_space *mapping) > return bdi_cap_account_dirty(mapping->backing_dev_info); > } > > -static inline bool mapping_cap_swap_backed(struct address_space *mapping) > -{ > - return bdi_cap_swap_backed(mapping->backing_dev_info); > -} > - > static inline int bdi_sched_wait(void *word) > { > schedule(); > diff --git a/mm/madvise.c b/mm/madvise.c > index a271adc..1383a89 100644 > --- a/mm/madvise.c > +++ b/mm/madvise.c > @@ -222,19 +222,22 @@ static long madvise_willneed(struct vm_area_struct *vma, > struct file *file = vma->vm_file; > > #ifdef CONFIG_SWAP > - if (!file || mapping_cap_swap_backed(file->f_mapping)) { > + if (!file) { > *prev = vma; > - if (!file) > - force_swapin_readahead(vma, start, end); > - else > - force_shm_swapin_readahead(vma, start, end, > - file->f_mapping); > + force_swapin_readahead(vma, start, end); > return 0; > } > -#endif > > + if (shmem_mapping(file->f_mapping)) { > + *prev = vma; > + force_shm_swapin_readahead(vma, start, end, > + file->f_mapping); > + return 0; > + } > +#else > if (!file) > return -EBADF; > +#endif > > if (file->f_mapping->a_ops->get_xip_mem) { > /* no bad return value, but ignore advice */ > diff --git a/mm/shmem.c b/mm/shmem.c > index 73ba1df..1b77eaf 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -191,11 +191,6 @@ static const struct inode_operations shmem_dir_inode_operations; > static const struct inode_operations shmem_special_inode_operations; > static const struct vm_operations_struct shmem_vm_ops; > > -static struct backing_dev_info shmem_backing_dev_info __read_mostly = { > - .ra_pages = 0, /* No readahead */ > - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, > -}; > - > static LIST_HEAD(shmem_swaplist); > static DEFINE_MUTEX(shmem_swaplist_mutex); > > @@ -765,11 +760,11 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) > goto redirty; > > /* > - * shmem_backing_dev_info's capabilities prevent regular writeback or > - * sync from ever calling shmem_writepage; but a stacking filesystem > - * might use ->writepage of its underlying filesystem, in which case > - * tmpfs should write out to swap only in response to memory pressure, > - * and not for the writeback threads or sync. > + * Our capabilities prevent regular writeback or sync from ever calling > + * shmem_writepage; but a stacking filesystem might use ->writepage of > + * its underlying filesystem, in which case tmpfs should write out to > + * swap only in response to memory pressure, and not for the writeback > + * threads or sync. > */ > if (!wbc->for_reclaim) { > WARN_ON_ONCE(1); /* Still happens? Tell us about it! */ > @@ -1415,7 +1410,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > inode->i_ino = get_next_ino(); > inode_init_owner(inode, dir, mode); > inode->i_blocks = 0; > - inode->i_mapping->backing_dev_info = &shmem_backing_dev_info; > + inode->i_mapping->backing_dev_info = &noop_backing_dev_info; > inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; > inode->i_generation = get_seconds(); > info = SHMEM_I(inode); > @@ -1461,7 +1456,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > > bool shmem_mapping(struct address_space *mapping) > { > - return mapping->backing_dev_info == &shmem_backing_dev_info; > + return mapping->host->i_sb->s_op == &shmem_ops; > } > > #ifdef CONFIG_TMPFS > @@ -3226,10 +3221,6 @@ int __init shmem_init(void) > if (shmem_inode_cachep) > return 0; > > - error = bdi_init(&shmem_backing_dev_info); > - if (error) > - goto out4; > - > error = shmem_init_inodecache(); > if (error) > goto out3; > @@ -3253,8 +3244,6 @@ out1: > out2: > shmem_destroy_inodecache(); > out3: > - bdi_destroy(&shmem_backing_dev_info); > -out4: > shm_mnt = ERR_PTR(error); > return error; > } > diff --git a/mm/swap.c b/mm/swap.c > index 8a12b33..4e0109a 100644 > --- a/mm/swap.c > +++ b/mm/swap.c > @@ -1138,8 +1138,6 @@ void __init swap_setup(void) > #ifdef CONFIG_SWAP > int i; > > - if (bdi_init(swapper_spaces[0].backing_dev_info)) > - panic("Failed to init swap bdi"); > for (i = 0; i < MAX_SWAPFILES; i++) { > spin_lock_init(&swapper_spaces[i].tree_lock); > INIT_LIST_HEAD(&swapper_spaces[i].i_mmap_nonlinear); > diff --git a/mm/swap_state.c b/mm/swap_state.c > index 9711342..1c137b6 100644 > --- a/mm/swap_state.c > +++ b/mm/swap_state.c > @@ -32,17 +32,12 @@ static const struct address_space_operations swap_aops = { > #endif > }; > > -static struct backing_dev_info swap_backing_dev_info = { > - .name = "swap", > - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED, > -}; > - > struct address_space swapper_spaces[MAX_SWAPFILES] = { > [0 ... MAX_SWAPFILES - 1] = { > .page_tree = RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN), > .i_mmap_writable = ATOMIC_INIT(0), > .a_ops = &swap_aops, > - .backing_dev_info = &swap_backing_dev_info, > + .backing_dev_info = &noop_backing_dev_info, > } > }; > > -- > 1.9.1 > > -- > 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 -- Jan Kara SUSE Labs, CR