Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
48 lines
1.9 KiB
C
48 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright 2023 Red Hat
|
|
*/
|
|
|
|
#ifndef VDO_PRIORITY_TABLE_H
|
|
#define VDO_PRIORITY_TABLE_H
|
|
|
|
#include <linux/list.h>
|
|
|
|
/*
|
|
* A priority_table is a simple implementation of a priority queue for entries with priorities that
|
|
* are small non-negative integer values. It implements the obvious priority queue operations of
|
|
* enqueuing an entry and dequeuing an entry with the maximum priority. It also supports removing
|
|
* an arbitrary entry. The priority of an entry already in the table can be changed by removing it
|
|
* and re-enqueuing it with a different priority. All operations have O(1) complexity.
|
|
*
|
|
* The links for the table entries must be embedded in the entries themselves. Lists are used to
|
|
* link entries in the table and no wrapper type is declared, so an existing list entry in an
|
|
* object can also be used to queue it in a priority_table, assuming the field is not used for
|
|
* anything else while so queued.
|
|
*
|
|
* The table is implemented as an array of queues (circular lists) indexed by priority, along with
|
|
* a hint for which queues are non-empty. Steven Skiena calls a very similar structure a "bounded
|
|
* height priority queue", but given the resemblance to a hash table, "priority table" seems both
|
|
* shorter and more apt, if somewhat novel.
|
|
*/
|
|
|
|
struct priority_table;
|
|
|
|
int __must_check vdo_make_priority_table(unsigned int max_priority,
|
|
struct priority_table **table_ptr);
|
|
|
|
void vdo_free_priority_table(struct priority_table *table);
|
|
|
|
void vdo_priority_table_enqueue(struct priority_table *table, unsigned int priority,
|
|
struct list_head *entry);
|
|
|
|
void vdo_reset_priority_table(struct priority_table *table);
|
|
|
|
struct list_head * __must_check vdo_priority_table_dequeue(struct priority_table *table);
|
|
|
|
void vdo_priority_table_remove(struct priority_table *table, struct list_head *entry);
|
|
|
|
bool __must_check vdo_is_priority_table_empty(struct priority_table *table);
|
|
|
|
#endif /* VDO_PRIORITY_TABLE_H */
|