pm24.git/include/linux/dcache.h, branch v2.6.29-rc1

shrink struct dentry

2008-12-31T23:07:38Z

struct dentry is one of the most critical structures in the kernel. So it's sad to see it going neglected. With CONFIG_PROFILING turned on (which is probably the common case at least for distros and kernel developers), sizeof(struct dcache) == 208 here (64-bit). This gives 19 objects per slab. I packed d_mounted into a hole, and took another 4 bytes off the inline name length to take the padding out from the end of the structure. This shinks it to 200 bytes. I could have gone the other way and increased the length to 40, but I'm aiming for a magic number, read on... I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant: why was this ever a good idea? The cookie system should increase its hash size or use a tree or something if lookups are a problem. Also the "fast dcookie lookups" in oprofile should be moved into the dcookie code -- how can oprofile possibly care about the dcookie_mutex? It gets dropped after get_dcookie() returns so it can't be providing any sort of protection. At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system with ~140 000 entries allocated. 192 is also a multiple of 64, so we get nice cacheline alignment on 64 and 32 byte line systems -- any given dentry will now require 3 cachelines to touch all fields wheras previously it would require 4. I know the inline name size was chosen quite carefully, however with the reduction in cacheline footprint, it should actually be just about as fast to do a name lookup for a 36 character name as it was before the patch (and faster for other sizes). The memory footprint savings for names which are <= 32 or > 36 bytes long should more than make up for the memory cost for 33-36 byte names. Performance is a feature... Signed-off-by: Al Viro

[PATCH vfs-2.6 2/6] vfs: add d_ancestor()

2008-10-23T09:13:16Z

This adds d_ancestor() instead of d_isparent(), then use it. If new_dentry == old_dentry, is_subdir() returns 1, looks strange. "new_dentry == old_dentry" is not subdir obviously. But I'm not checking callers for now, so this keeps current behavior. Signed-off-by: OGAWA Hirofumi

[PATCH] kill d_alloc_anon

2008-10-23T09:13:02Z

Remove d_alloc_anon now that no users are left. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

[PATCH] new helper: d_obtain_alias

2008-10-23T09:13:00Z

The calling conventions of d_alloc_anon are rather unfortunate for all users, and it's name is not very descriptive either. Add d_obtain_alias as a new exported helper that drops the inode reference in the failure case, too and allows to pass-through NULL pointers and inodes to allow for tail-calls in the export operations. Incidentally this helper already existed as a private function in libfs.c as exportfs_d_alloc so kill that one and switch the callers to d_obtain_alias. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

[PATCH] change d_add_ci argument ordering

2008-08-25T05:18:05Z

As pointed out during review d_add_ci argument order should match d_add, so switch the dentry and inode arguments. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro

dcache: Add case-insensitive support d_ci_add() routine

2008-07-28T06:58:39Z

This add a dcache entry to the dcache for lookup, but changing the name that is associated with the entry rather than the one passed in to the lookup routine. First, it sees if the case-exact match already exists in the dcache and uses it if one exists. Otherwise, it allocates a new node with the new name and splices it into the dcache. Original code from ntfs_lookup in fs/ntfs/namei.c by Anton Altaparmakov. Signed-off-by: Barry Naujok Signed-off-by: Anton Altaparmakov Acked-by: Christoph Hellwig

Merge branch 'linus' into core/rcu

2008-07-11T08:46:50Z

Conflicts: include/linux/rculist.h kernel/rcupreempt.c Signed-off-by: Ingo Molnar

[patch 2/4] fs: make struct file arg to d_path const

2008-06-23T15:52:30Z

Signed-off-by: Jan Engelhardt Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro

rcu: split list.h and move rcu-protected lists into rculist.h

2008-05-19T08:01:37Z

Move rcu-protected lists from list.h into a new header file rculist.h. This is done because list are a very used primitive structure all over the kernel and it's currently impossible to include other header files in this list.h without creating some circular dependencies. For example, list.h implements rcu-protected list and uses rcu_dereference() without including rcupdate.h. It actually compiles because users of rcu_dereference() are macros. Others RCU functions could be used too but aren't probably because of this. Therefore this patch creates rculist.h which includes rcupdates without to many changes/troubles. Signed-off-by: Franck Bui-Huu Acked-by: Paul E. McKenney Acked-by: Josh Triplett Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar

Remove "#ifdef KERNEL" checks from unexported headers

2008-04-30T15:29:54Z

Remove the "#ifdef __KERNEL__" tests from unexported header files in linux/include whose entire contents are wrapped in that preprocessor test. Signed-off-by: Robert P. J. Day Cc: David Woodhouse Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds