kernel_optimize_test/include/linux/async.h
Tejun Heo 52722794d6 async: keep pending tasks on async_domain and remove async_pending
Async kept single global pending list and per-domain running lists.
When an async item is queued, it's put on the global pending list.
The item is moved to the per-domain running list when its execution
starts.

At this point, this design complicates execution and synchronization
without bringing any benefit.  The list only matters for
synchronization which doesn't care whether a given async item is
pending or executing.  Also, global synchronization is done by
iterating through all active registered async_domains, so the global
async_pending list doesn't help anything either.

Rename async_domain->running to async_domain->pending and put async
items directly there and remove when execution completes.  This
simplifies lowest_in_progress() a lot - the first item on the pending
list is the one with the lowest cookie, and async_run_entry_fn()
doesn't have to mess with moving the item from pending to running.

After the change, whether a domain is empty or not can be trivially
determined by looking at async_domain->pending.  Remove
async_domain->count and use list_empty() on pending instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <djbw@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-23 09:32:30 -08:00

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1.8 KiB
C

/*
* async.h: Asynchronous function calls for boot performance
*
* (C) Copyright 2009 Intel Corporation
* Author: Arjan van de Ven <arjan@linux.intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*/
#ifndef __ASYNC_H__
#define __ASYNC_H__
#include <linux/types.h>
#include <linux/list.h>
typedef u64 async_cookie_t;
typedef void (async_func_ptr) (void *data, async_cookie_t cookie);
struct async_domain {
struct list_head node;
struct list_head pending;
unsigned registered:1;
};
/*
* domain participates in global async_synchronize_full
*/
#define ASYNC_DOMAIN(_name) \
struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \
.pending = LIST_HEAD_INIT(_name.pending), \
.registered = 1 }
/*
* domain is free to go out of scope as soon as all pending work is
* complete, this domain does not participate in async_synchronize_full
*/
#define ASYNC_DOMAIN_EXCLUSIVE(_name) \
struct async_domain _name = { .node = LIST_HEAD_INIT(_name.node), \
.pending = LIST_HEAD_INIT(_name.pending), \
.registered = 0 }
extern async_cookie_t async_schedule(async_func_ptr *ptr, void *data);
extern async_cookie_t async_schedule_domain(async_func_ptr *ptr, void *data,
struct async_domain *domain);
void async_unregister_domain(struct async_domain *domain);
extern void async_synchronize_full(void);
extern void async_synchronize_full_domain(struct async_domain *domain);
extern void async_synchronize_cookie(async_cookie_t cookie);
extern void async_synchronize_cookie_domain(async_cookie_t cookie,
struct async_domain *domain);
extern bool current_is_async(void);
#endif