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author | Paul Menage <menage@google.com> | 2007-10-18 23:40:22 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 11:53:41 -0700 |
commit | 8707d8b8c0cbdf4441507f8dded194167da896c7 (patch) | |
tree | 1e9ac6b15027bd55263378e551c1595a937d66d6 /include/linux/prio_heap.h | |
parent | 020958b6272882c1a8bfbe5f3e0927f3845c2698 (diff) | |
download | kernel_samsung_espresso10-8707d8b8c0cbdf4441507f8dded194167da896c7.zip kernel_samsung_espresso10-8707d8b8c0cbdf4441507f8dded194167da896c7.tar.gz kernel_samsung_espresso10-8707d8b8c0cbdf4441507f8dded194167da896c7.tar.bz2 |
Fix cpusets update_cpumask
Cause writes to cpuset "cpus" file to update cpus_allowed for member tasks:
- collect batches of tasks under tasklist_lock and then call
set_cpus_allowed() on them outside the lock (since this can sleep).
- add a simple generic priority heap type to allow efficient collection
of batches of tasks to be processed without duplicating or missing any
tasks in subsequent batches.
- make "cpus" file update a no-op if the mask hasn't changed
- fix race between update_cpumask() and sched_setaffinity() by making
sched_setaffinity() post-check that it's not running on any cpus outside
cpuset_cpus_allowed().
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/prio_heap.h')
-rw-r--r-- | include/linux/prio_heap.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/include/linux/prio_heap.h b/include/linux/prio_heap.h new file mode 100644 index 0000000..0809435 --- /dev/null +++ b/include/linux/prio_heap.h @@ -0,0 +1,58 @@ +#ifndef _LINUX_PRIO_HEAP_H +#define _LINUX_PRIO_HEAP_H + +/* + * Simple insertion-only static-sized priority heap containing + * pointers, based on CLR, chapter 7 + */ + +#include <linux/gfp.h> + +/** + * struct ptr_heap - simple static-sized priority heap + * @ptrs - pointer to data area + * @max - max number of elements that can be stored in @ptrs + * @size - current number of valid elements in @ptrs (in the range 0..@size-1 + * @gt: comparison operator, which should implement "greater than" + */ +struct ptr_heap { + void **ptrs; + int max; + int size; + int (*gt)(void *, void *); +}; + +/** + * heap_init - initialize an empty heap with a given memory size + * @heap: the heap structure to be initialized + * @size: amount of memory to use in bytes + * @gfp_mask: mask to pass to kmalloc() + * @gt: comparison operator, which should implement "greater than" + */ +extern int heap_init(struct ptr_heap *heap, size_t size, gfp_t gfp_mask, + int (*gt)(void *, void *)); + +/** + * heap_free - release a heap's storage + * @heap: the heap structure whose data should be released + */ +void heap_free(struct ptr_heap *heap); + +/** + * heap_insert - insert a value into the heap and return any overflowed value + * @heap: the heap to be operated on + * @p: the pointer to be inserted + * + * Attempts to insert the given value into the priority heap. If the + * heap is full prior to the insertion, then the resulting heap will + * consist of the smallest @max elements of the original heap and the + * new element; the greatest element will be removed from the heap and + * returned. Note that the returned element will be the new element + * (i.e. no change to the heap) if the new element is greater than all + * elements currently in the heap. + */ +extern void *heap_insert(struct ptr_heap *heap, void *p); + + + +#endif /* _LINUX_PRIO_HEAP_H */ |