This patch adds an iterator function for the idr data structure. Compared
to just iterating through the idr with an integer and idr_find, this
iterator is (almost, but not quite) linear in the number of elements, as
opposed to the number of integers in the range covered by the idr. This
makes a difference for sparse idrs, but more importantly, it's a nicer way
to iterate through the elements.
The drm subsystem is moving to idr for tracking contexts and drawables, and
with this change, we can use the idr exclusively for tracking these
resources.
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Kristian Hoegsberg <krh@redhat.com>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement idr based id allocator. ida is used the same way idr is
used but lacks id -> ptr translation and thus consumes much less
memory. struct ida_bitmap is attached as leaf nodes to idr tree which
is managed by the idr code. Each ida_bitmap is 128bytes long and
contains slightly less than a thousand slots.
ida is more aggressive with releasing extra resources acquired using
ida_pre_get(). After every successful id allocation, ida frees one
reserved idr_layer if possible. Reserved ida_bitmap is not freed
automatically but only one ida_bitmap is reserved and it's almost
always used right away. Under most circumstances, ida won't hold on
to memory for too long which isn't actively used.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Separate out idr_mark_full() from sub_alloc() and make marking the
allocated slot full the responsibility of idr_get_new_above_int().
Allocation part of idr_get_new_above_int() is renamed to
idr_get_empty_slot(). New idr_get_new_above_int() allocates a slot
using the function, install the user pointer and marks it full using
idr_mark_full().
This change doesn't introduce any behavior change. This will be
used by ida.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In sub_alloc(), when bitmap search fails, it goes up one level to
continue search. This is done by updating the id cursor and searching
the upper level again. If the cursor was at the end of the upper
level, we need to go further than that.
This wasn't implemented and when that happens the part of the cursor
which indexes into the upper level wraps and sub_alloc() ends up
searching the wrong bitmap. It allocates id which doesn't match the
actual slot.
This patch fixes this by restarting from the top if the search needs
to go higher than one level.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in
source files, including:
* make multi-line initial descriptions single line
* denote some function names, constants and structs as such
* change erroneous opening '/*' to '/**' in a few places
* reword some text for clarity
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#
set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
done
The script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently, the code in lib/idr.c uses a bare spin_lock(&idp->lock) to do
internal locking. This is a nasty trap for code that might call idr
functions from different contexts; for example, it seems perfectly
reasonable to call idr_get_new() from process context and idr_remove() from
interrupt context -- but with the current locking this would lead to a
potential deadlock.
The simplest fix for this is to just convert the idr locking to use
spin_lock_irqsave().
In particular, this fixes a very complicated locking issue detected by
lockdep, involving the ib_ipoib driver's priv->lock and dev->_xmit_lock,
which get involved with the ib_sa module's query_idr.lock.
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Zach Brown <zach.brown@oracle.com>,
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds idr_replace() to replace an existing pointer in a single
operation.
Device-mapper will use this to update the pointer it stored against a given
id.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix a bug which was reported and diagnosed by
Stefan Jones <stefan.jones@churchillrandoms.co.uk>
IDR trees include a cache of idr_layer objects. There's no way to destroy
this cache, so when we discard an overall idr tree we end up leaking some
memory.
Add and use idr_destroy() for this. v9fs and infiniband also need to use
idr_destroy() to avoid leaks.
Or, we make the cache global, like radix_tree_preload(). Which is probably
better. Later.
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Robert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There is an off by one problem with idr_get_new_above.
The comment and function name suggest that it will return an id >
starting_id, but it actually returned an id >= starting_id, and kernel
callers other than inotify treated it as such.
The patch below fixes the comment, and fixes inotifys usage. The
function name still doesn't match the behaviour, but it never did.
Signed-off-by: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes overrun of array pa:
92 struct idr_layer *pa[MAX_LEVEL];
in
98 l = idp->layers;
99 pa[l--] = NULL;
by passing idp->layers, set in
202 idp->layers = layers;
to function sub_alloc in
203 v = sub_alloc(idp, ptr, &id);
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Kristian Hoegsberg