Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030352AbVKHVE7 (ORCPT ); Tue, 8 Nov 2005 16:04:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030357AbVKHVEw (ORCPT ); Tue, 8 Nov 2005 16:04:52 -0500 Received: from omx3-ext.sgi.com ([192.48.171.20]:22184 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S1030355AbVKHVEq (ORCPT ); Tue, 8 Nov 2005 16:04:46 -0500 Date: Tue, 8 Nov 2005 13:04:27 -0800 (PST) From: Christoph Lameter To: akpm@osdl.org Cc: Mike Kravetz , linux-kernel@vger.kernel.org, Dave Hansen , Nick Piggin , linux-mm@kvack.org, torvalds@osdl.org, Christoph Lameter , Hirokazu Takahashi , Magnus Damm , KAMEZAWA Hiroyuki , Paul Jackson , Marcelo Tosatti , Andi Kleen Message-Id: <20051108210417.31330.72381.sendpatchset@schroedinger.engr.sgi.com> In-Reply-To: <20051108210246.31330.61756.sendpatchset@schroedinger.engr.sgi.com> References: <20051108210246.31330.61756.sendpatchset@schroedinger.engr.sgi.com> Subject: [PATCH 6/8] Direct Migration V2: Avoid writeback / page_migrate() method Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8246 Lines: 246 Migrate a page with buffers without requiring writeback This introduces a new address space operation migrate_page() that may be used by a filesystem to implement its own version of page migration. A version is provided that migrates buffers attached to pages. Some filesystems (ext2, ext3, xfs) are modified to utilize this feature. The swapper address space operation are modified so that a regular migrate_pages() will occur for anonymous pages without writeback (migrate_pages forces every anonymous page to have a swap entry). V1->V2: - Fix CONFIG_MIGRATION handling Signed-off-by: Mike Kravetz Signed-off-by: Christoph Lameter Index: linux-2.6.14-mm1/include/linux/fs.h =================================================================== --- linux-2.6.14-mm1.orig/include/linux/fs.h 2005-11-07 11:48:46.000000000 -0800 +++ linux-2.6.14-mm1/include/linux/fs.h 2005-11-08 10:18:51.000000000 -0800 @@ -332,6 +332,8 @@ struct address_space_operations { loff_t offset, unsigned long nr_segs); struct page* (*get_xip_page)(struct address_space *, sector_t, int); + /* migrate the contents of a page to the specified target */ + int (*migrate_page) (struct page *, struct page *); }; struct backing_dev_info; @@ -1679,6 +1681,12 @@ extern void simple_release_fs(struct vfs extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t); +#ifdef CONFIG_MIGRATION +extern int buffer_migrate_page(struct page *, struct page *); +#else +#define buffer_migrate_page(a,b) NULL +#endif + extern int inode_change_ok(struct inode *, struct iattr *); extern int __must_check inode_setattr(struct inode *, struct iattr *); Index: linux-2.6.14-mm1/mm/swap_state.c =================================================================== --- linux-2.6.14-mm1.orig/mm/swap_state.c 2005-11-07 11:48:49.000000000 -0800 +++ linux-2.6.14-mm1/mm/swap_state.c 2005-11-08 10:18:51.000000000 -0800 @@ -26,6 +26,7 @@ static struct address_space_operations s .writepage = swap_writepage, .sync_page = block_sync_page, .set_page_dirty = __set_page_dirty_nobuffers, + .migrate_page = migrate_page, }; static struct backing_dev_info swap_backing_dev_info = { Index: linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_aops.c =================================================================== --- linux-2.6.14-mm1.orig/fs/xfs/linux-2.6/xfs_aops.c 2005-11-07 11:48:07.000000000 -0800 +++ linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_aops.c 2005-11-08 10:18:51.000000000 -0800 @@ -1348,4 +1348,5 @@ struct address_space_operations linvfs_a .commit_write = generic_commit_write, .bmap = linvfs_bmap, .direct_IO = linvfs_direct_IO, + .migrate_page = buffer_migrate_page, }; Index: linux-2.6.14-mm1/fs/buffer.c =================================================================== --- linux-2.6.14-mm1.orig/fs/buffer.c 2005-11-07 11:48:25.000000000 -0800 +++ linux-2.6.14-mm1/fs/buffer.c 2005-11-08 10:18:51.000000000 -0800 @@ -3026,6 +3026,70 @@ asmlinkage long sys_bdflush(int func, lo } /* + * Migration function for pages with buffers. This function can only be used + * if the underlying filesystem guarantees that no other references to "page" + * exist. + */ +#ifdef CONFIG_MIGRATION +int buffer_migrate_page(struct page *newpage, struct page *page) +{ + struct address_space *mapping = page->mapping; + struct buffer_head *bh, *head; + + if (!mapping) + return -EAGAIN; + + if (!page_has_buffers(page)) + return migrate_page(newpage, page); + + head = page_buffers(page); + + if (migrate_page_remove_references(newpage, page, 3)) + return -EAGAIN; + + spin_lock(&mapping->private_lock); + + bh = head; + do { + get_bh(bh); + lock_buffer(bh); + bh = bh->b_this_page; + + } while (bh != head); + + ClearPagePrivate(page); + set_page_private(newpage, page_private(page)); + set_page_private(page, 0); + put_page(page); + get_page(newpage); + + bh = head; + do { + set_bh_page(bh, newpage, bh_offset(bh)); + bh = bh->b_this_page; + + } while (bh != head); + + SetPagePrivate(newpage); + spin_unlock(&mapping->private_lock); + + migrate_page_copy(newpage, page); + + spin_lock(&mapping->private_lock); + bh = head; + do { + unlock_buffer(bh); + put_bh(bh); + bh = bh->b_this_page; + + } while (bh != head); + spin_unlock(&mapping->private_lock); + + return 0; +} +#endif + +/* * Buffer-head allocation */ static kmem_cache_t *bh_cachep; Index: linux-2.6.14-mm1/fs/ext3/inode.c =================================================================== --- linux-2.6.14-mm1.orig/fs/ext3/inode.c 2005-11-07 11:48:24.000000000 -0800 +++ linux-2.6.14-mm1/fs/ext3/inode.c 2005-11-08 10:18:51.000000000 -0800 @@ -1562,6 +1562,7 @@ static struct address_space_operations e .invalidatepage = ext3_invalidatepage, .releasepage = ext3_releasepage, .direct_IO = ext3_direct_IO, + .migrate_page = buffer_migrate_page, }; static struct address_space_operations ext3_writeback_aops = { @@ -1575,6 +1576,7 @@ static struct address_space_operations e .invalidatepage = ext3_invalidatepage, .releasepage = ext3_releasepage, .direct_IO = ext3_direct_IO, + .migrate_page = buffer_migrate_page, }; static struct address_space_operations ext3_journalled_aops = { Index: linux-2.6.14-mm1/fs/ext2/inode.c =================================================================== --- linux-2.6.14-mm1.orig/fs/ext2/inode.c 2005-11-07 11:48:07.000000000 -0800 +++ linux-2.6.14-mm1/fs/ext2/inode.c 2005-11-08 10:18:51.000000000 -0800 @@ -706,6 +706,7 @@ struct address_space_operations ext2_aop .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, + .migrate_page = buffer_migrate_page, }; struct address_space_operations ext2_aops_xip = { @@ -723,6 +724,7 @@ struct address_space_operations ext2_nob .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, + .migrate_page = buffer_migrate_page, }; /* Index: linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_buf.c =================================================================== --- linux-2.6.14-mm1.orig/fs/xfs/linux-2.6/xfs_buf.c 2005-11-07 11:48:07.000000000 -0800 +++ linux-2.6.14-mm1/fs/xfs/linux-2.6/xfs_buf.c 2005-11-08 10:18:51.000000000 -0800 @@ -1568,6 +1568,7 @@ xfs_mapping_buftarg( struct address_space *mapping; static struct address_space_operations mapping_aops = { .sync_page = block_sync_page, + .migrate_page = fail_migrate_page, }; inode = new_inode(bdev->bd_inode->i_sb); Index: linux-2.6.14-mm1/mm/vmscan.c =================================================================== --- linux-2.6.14-mm1.orig/mm/vmscan.c 2005-11-08 10:16:58.000000000 -0800 +++ linux-2.6.14-mm1/mm/vmscan.c 2005-11-08 10:19:30.000000000 -0800 @@ -571,6 +571,15 @@ keep: return reclaimed; } +/* + * Non migratable page + */ +int fail_migrate_page(struct page *newpage, struct page *page) +{ + return -EIO; +} + + #ifdef CONFIG_MIGRATION /* * swapout a single page @@ -905,6 +914,11 @@ redo: if (!mapping) goto unlock_both; + if (mapping->a_ops->migrate_page) { + rc = mapping->a_ops->migrate_page(newpage, page); + goto unlock_both; + } + /* * Trigger writeout if page is dirty */ Index: linux-2.6.14-mm1/include/linux/swap.h =================================================================== --- linux-2.6.14-mm1.orig/include/linux/swap.h 2005-11-08 10:16:58.000000000 -0800 +++ linux-2.6.14-mm1/include/linux/swap.h 2005-11-08 10:18:51.000000000 -0800 @@ -186,6 +186,11 @@ extern int migrate_pages(struct list_hea extern int migrate_page(struct page *, struct page *); extern int migrate_page_remove_references(struct page *, struct page *, int); extern void migrate_page_copy(struct page *, struct page *); +extern int fail_migrate_page(struct page *, struct page *); +#else +/* Possible settings for the migrate_page() method in address_operations */ +#define migrate_page(a,b) NULL +#define fail_migrate_page(a,b) NULL #endif #ifdef CONFIG_MMU - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/