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async: Asynchronous function calls to speed up kernel boot Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-08 00:45:46 +08:00
/*
* 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.
*/
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
#ifndef __ASYNC_H__
#define __ASYNC_H__
async: Asynchronous function calls to speed up kernel boot Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-08 00:45:46 +08:00
#include <linux/types.h>
#include <linux/list.h>
typedef u64 async_cookie_t;
async: rename and redefine async_func_ptr A function type is typically defined as typedef ret_type (*func)(args..) but async_func_ptr is not. Redefine it. Also rename async_func_ptr to async_func_t for _func_t suffix is more generic. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com>
2013-03-13 04:59:14 +08:00
typedef void (*async_func_t) (void *data, async_cookie_t cookie);
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
struct async_domain {
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>
2013-01-24 01:32:30 +08:00
struct list_head pending;
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
unsigned registered:1;
};
/*
* domain participates in global async_synchronize_full
*/
#define ASYNC_DOMAIN(_name) \
async: remove unused @node from struct async_domain The @node in struct async_domain is unused after we introduce async_global_pending, remove it. tj: Unnecessary whitespace adjustments dropped. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com>
2013-03-13 04:59:14 +08:00
struct async_domain _name = { .pending = LIST_HEAD_INIT(_name.pending), \
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
.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) \
async: remove unused @node from struct async_domain The @node in struct async_domain is unused after we introduce async_global_pending, remove it. tj: Unnecessary whitespace adjustments dropped. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com>
2013-03-13 04:59:14 +08:00
struct async_domain _name = { .pending = LIST_HEAD_INIT(_name.pending), \
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
.registered = 0 }
async: Asynchronous function calls to speed up kernel boot Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-08 00:45:46 +08:00
async: rename and redefine async_func_ptr A function type is typically defined as typedef ret_type (*func)(args..) but async_func_ptr is not. Redefine it. Also rename async_func_ptr to async_func_t for _func_t suffix is more generic. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com>
2013-03-13 04:59:14 +08:00
extern async_cookie_t async_schedule(async_func_t func, void *data);
extern async_cookie_t async_schedule_domain(async_func_t func, void *data,
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
struct async_domain *domain);
[SCSI] async: make async_synchronize_full() flush all work regardless of domain In response to an async related regression James noted: "My theory is that this is an init problem: The assumption in a lot of our code is that async_synchronize_full() waits for everything ... even the domain specific async schedules, which isn't true." ...so make this assumption true. Each domain, including the default one, registers itself on a global domain list when work is scheduled. Once all entries complete it exits that list. Waiting for the list to be empty syncs all in-flight work across all domains. Domains can opt-out of global syncing if they are declared as exclusive ASYNC_DOMAIN_EXCLUSIVE(). All stack-based domains have been declared exclusive since the domain may go out of scope as soon as the last work item completes. Statically declared domains are mostly ok, but async_unregister_domain() is there to close any theoretical races with pending async_synchronize_full waiters at module removal time. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Reported-by: Meelis Roos <mroos@linux.ee> Reported-by: Eldad Zack <eldadzack@gmail.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:30 +08:00
void async_unregister_domain(struct async_domain *domain);
async: Asynchronous function calls to speed up kernel boot Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-08 00:45:46 +08:00
extern void async_synchronize_full(void);
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
extern void async_synchronize_full_domain(struct async_domain *domain);
async: Asynchronous function calls to speed up kernel boot Right now, most of the kernel boot is strictly synchronous, such that various hardware delays are done sequentially. In order to make the kernel boot faster, this patch introduces infrastructure to allow doing some of the initialization steps asynchronously, which will hide significant portions of the hardware delays in practice. In order to not change device order and other similar observables, this patch does NOT do full parallel initialization. Rather, it operates more in the way an out of order CPU does; the work may be done out of order and asynchronous, but the observable effects (instruction retiring for the CPU) are still done in the original sequence. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-08 00:45:46 +08:00
extern void async_synchronize_cookie(async_cookie_t cookie);
async: Rename _special -> _domain for clarity. Rename the async_*_special() functions to async_*_domain(), which describes the purpose of these functions much better. [Broke up long lines to silence checkpatch] Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2009-01-20 22:31:31 +08:00
extern void async_synchronize_cookie_domain(async_cookie_t cookie,
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
struct async_domain *domain);
workqueue: implement current_is_async() This function queries whether %current is an async worker executing an async item. This will be used to implement warning on synchronous request_module() from async workers. Signed-off-by: Tejun Heo <tj@kernel.org>
2013-01-19 06:05:56 +08:00
extern bool current_is_async(void);
[SCSI] async: introduce 'async_domain' type This is in preparation for teaching async_synchronize_full() to sync all pending async work, and not just on the async_running domain. This conversion is functionally equivalent, just embedding the existing list in a new async_domain type. The .registered attribute is used in a later patch to distinguish between domains that want to be flushed by async_synchronize_full() versus those that only expect async_synchronize_{full|cookie}_domain to be used for flushing. [jejb: add async.h to scsi_priv.h for struct async_domain] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-07-10 10:33:25 +08:00
#endif