kernel/git/stable/linux.git/mm/migrate.c, branch linux-2.6.21.y

page migration: fix NR_FILE_PAGES accounting

2007-04-24T15:23:08+00:00

NR_FILE_PAGES must be accounted for depending on the zone that the page belongs to. If we replace the page in the radix tree then we may have to shift the count to another zone. Suggested-by: Ethan Solomita Eventually-typed-in-by: Christoph Lameter Cc: Martin Bligh Cc: Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Page migration: Fix vma flag checking

2007-03-05T15:57:51+00:00

Currently we do not check for vma flags if sys_move_pages is called to move individual pages. If sys_migrate_pages is called to move pages then we check for vm_flags that indicate a non migratable vma but that still includes VM_LOCKED and we can migrate mlocked pages. Extract the vma_migratable check from mm/mempolicy.c, fix it and put it into migrate.h so that is can be used from both locations. Problem was spotted by Lee Schermerhorn Signed-off-by: Christoph Lameter Signed-off-by: Lee Schermerhorn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] radix-tree: RCU lockless readside

2006-12-07T16:39:25+00:00

Make radix tree lookups safe to be performed without locks. Readers are protected against nodes being deleted by using RCU based freeing. Readers are protected against new node insertion by using memory barriers to ensure the node itself will be properly written before it is visible in the radix tree. Each radix tree node keeps a record of their height (above leaf nodes). This height does not change after insertion -- when the radix tree is extended, higher nodes are only inserted in the top. So a lookup can take the pointer to what is *now* the root node, and traverse down it even if the tree is concurrently extended and this node becomes a subtree of a new root. "Direct" pointers (tree height of 0, where root->rnode points directly to the data item) are handled by using the low bit of the pointer to signal whether rnode is a direct pointer or a pointer to a radix tree node. When a reader wants to traverse the next branch, they will take a copy of the pointer. This pointer will be either NULL (and the branch is empty) or non-NULL (and will point to a valid node). [akpm@osdl.org: cleanups] [Lee.Schermerhorn@hp.com: bugfixes, comments, simplifications] [clameter@sgi.com: build fix] Signed-off-by: Nick Piggin Cc: "Paul E. McKenney" Signed-off-by: Lee Schermerhorn Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix sys_move_pages when a NULL node list is passed

2006-11-03T20:27:59+00:00

sys_move_pages() uses vmalloc() to allocate an array of structures that is fills with information passed from user mode and then passes to do_stat_pages() (in the case the node list is NULL). do_stat_pages() depends on a marker in the node field of the structure to decide how large the array is and this marker is correctly inserted into the last element of the array. However, vmalloc() doesn't zero the memory it allocates and if the user passes NULL for the node list, then the node fields are not filled in (except for the end marker). If the memory the vmalloc() returned happend to have a word with the marker value in it in just the right place, do_pages_stat will fail to fill the status field of part of the array and we will return (random) kernel data to user mode. Signed-off-by: Stephen Rothwell Cc: Christoph Lameter Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] BLOCK: Make it possible to disable the block layer [try #6]

2006-09-30T18:52:31+00:00

Make it possible to disable the block layer. Not all embedded devices require it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require the block layer to be present. This patch does the following: (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev support. (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls an item that uses the block layer. This includes: (*) Block I/O tracing. (*) Disk partition code. (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS. (*) The SCSI layer. As far as I can tell, even SCSI chardevs use the block layer to do scheduling. Some drivers that use SCSI facilities - such as USB storage - end up disabled indirectly from this. (*) Various block-based device drivers, such as IDE and the old CDROM drivers. (*) MTD blockdev handling and FTL. (*) JFFS - which uses set_bdev_super(), something it could avoid doing by taking a leaf out of JFFS2's book. (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is, however, still used in places, and so is still available. (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and parts of linux/fs.h. (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK. (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK. (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK is not enabled. (*) fs/no-block.c is created to hold out-of-line stubs and things that are required when CONFIG_BLOCK is not set: (*) Default blockdev file operations (to give error ENODEV on opening). (*) Makes some /proc changes: (*) /proc/devices does not list any blockdevs. (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK. (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK. (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if given command other than Q_SYNC or if a special device is specified. (*) In init/do_mounts.c, no reference is made to the blockdev routines if CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2. (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return error ENOSYS by way of cond_syscall if so). (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if CONFIG_BLOCK is not set, since they can't then happen. Signed-Off-By: David Howells Signed-off-by: Jens Axboe

[PATCH] BLOCK: Stop fallback_migrate_page() from using page_has_buffers() [try #6]

2006-09-30T18:31:20+00:00

Stop fallback_migrate_page() from using page_has_buffers() since that might not be available. Use PagePrivate() instead since that's more general. Signed-Off-By: David Howells Signed-off-by: Jens Axboe

[PATCH] Define easier to handle GFP_THISNODE

2006-09-26T15:48:50+00:00

In many places we will need to use the same combination of flags. Specify a single GFP_THISNODE definition for ease of use in gfp.h. Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] sys_move_pages: Do not fall back to other nodes

2006-09-26T15:48:50+00:00

If the user specified a node where we should move the page to then we really do not want any other node. Signed-off-by: Christoph Lameter Cc: Andy Whitcroft Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Allow migration of mlocked pages

2006-06-25T17:00:55+00:00

Hugh clarified the role of VM_LOCKED. So we can now implement page migration for mlocked pages. Allow the migration of mlocked pages. This means that try_to_unmap must unmap mlocked pages in the migration case. Signed-off-by: Christoph Lameter Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] page migration: Support a vma migration function

2006-06-25T17:00:55+00:00

Hooks for calling vma specific migration functions With this patch a vma may define a vma->vm_ops->migrate function. That function may perform page migration on its own (some vmas may not contain page structs and therefore cannot be handled by regular page migration. Pages in a vma may require special preparatory treatment before migration is possible etc) . Only mmap_sem is held when the migration function is called. The migrate() function gets passed two sets of nodemasks describing the source and the target of the migration. The flags parameter either contains MPOL_MF_MOVE which means that only pages used exclusively by the specified mm should be moved or MPOL_MF_MOVE_ALL which means that pages shared with other processes should also be moved. The migration function returns 0 on success or an error condition. An error condition will prevent regular page migration from occurring. On its own this patch cannot be included since there are no users for this functionality. But it seems that the uncached allocator will need this functionality at some point. Signed-off-by: Christoph Lameter Cc: Hugh Dickins Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds