Commit graph

13 commits

Author SHA1 Message Date
Nadia Derbey
f9c46d6ea5 idr: make idr_find rcu-safe
Make idr_find rcu-safe: it can now be called inside an rcu_read critical
section.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Jim Houston <jim.houston@comcast.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:42 -07:00
Nadia Derbey
944ca05c7b idr: error checking factorization
Do some code factorization in the return code analysis.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Jim Houston <jim.houston@comcast.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:41 -07:00
Nadia Derbey
2027d1abc2 idr: change the idr structure
After scalability problems have been detected when using the sysV ipcs, I have
proposed to use an RCU based implementation of the IDR api instead (see
threads http://lkml.org/lkml/2008/4/11/212 and
http://lkml.org/lkml/2008/4/29/295).

This resulted in many people asking to convert the idr API and make it rcu
safe (because most of the code was duplicated and thus unmaintanable and
unreviewable).

So here is a first attempt.

The important change wrt to the idr API itself is during idr removes: idr
layers are freed after a grace period, instead of being moved to the free
list.

The important change wrt to ipcs, is that idr_find() can now be called
locklessly inside a rcu read critical section.

Here are the results I've got for the pmsg test sent by Manfred:

   2.6.25-rc3-mm1   2.6.25-rc3-mm1+   2.6.25-mm1   Patched 2.6.25-mm1
1         1168441           1064021       876000               947488
2         1094264            921059      1549592              1730685
3         2082520           1738165      1694370              2324880
4         2079929           1695521       404553              2400408
5         2898758            406566       391283              3246580
6         2921417            261275       263249              3752148
7         3308761            126056       191742              4243142
8         3329456            100129       141722              4275780

1st column: stock 2.6.25-rc3-mm1
2nd column: 2.6.25-rc3-mm1 + ipc patches (store ipcs into idrs)
3nd column: stock 2.6.25-mm1
4th column: 2.6.25-mm1 + this pacth series.

This patch:

Add an rcu_head to the idr_layer structure in order to free it after a grace
period.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Jim Houston <jim.houston@comcast.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:41 -07:00
Akinobu Mita
199f0ca514 idr: create idr_layer_cache at boot time
Avoid a possible kmem_cache_create() failure by creating idr_layer_cache
unconditionary at boot time rather than creating it on-demand when idr_init()
is called the first time.

This change also enables us to eliminate the check every time idr_init() is
called.

[akpm@linux-foundation.org: rename init_id_cache() to idr_init_cache()]
[akpm@linux-foundation.org: fix alpha build]
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:25 -07:00
Kristian Hoegsberg
23936cc0b5 lib: add idr_remove_all
Remove all ids from the given idr tree.  idr_destroy() only frees up
unused, cached idp_layers, but this function will remove all id mappings
and leave all idp_layers unused.

A typical clean-up sequence for objects stored in an idr tree, will use
idr_for_each() to free all objects, if necessay, then idr_remove_all() to
remove all ids, and idr_destroy() to free up the cached idr_layers.

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>
2007-07-16 09:05:34 -07:00
Kristian Hoegsberg
96d7fa421e lib: add idr_for_each()
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>
2007-07-16 09:05:34 -07:00
Tejun Heo
72dba584b6 ida: implement idr based id allocator
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>
2007-07-11 16:09:03 -07:00
Ingo Molnar
e4d9191885 [PATCH] lockdep: locking init debugging improvement
Locking init improvement:

 - introduce and use __SPIN_LOCK_UNLOCKED for array initializations,
   to pass in the name string of locks, used by debugging

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03 15:27:02 -07:00
Jeff Mahoney
5806f07cd2 [PATCH] lib: add idr_replace
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>
2006-06-26 09:58:34 -07:00
Luben Tuikov
f668ab1acc include/linux: enclose idr.h in #ifndef
This patch encloses the idr.h header file in
#ifndef __IDR_H__ macro.

Signed-off-by: Luben Tuikov <luben_tuikov@adaptec.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-11-08 17:14:08 +01:00
Al Viro
fd4f2df24b [PATCH] gfp_t: lib/*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:47 -07:00
Andrew Morton
8d3b35914a [PATCH] inotify/idr leak fix
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>
2005-10-23 16:38:39 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
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!
2005-04-16 15:20:36 -07:00