rename module_name to strategy_module_name to avoid fatal shadowing of
module_name() when compiled with older external gcc. NFC

Fix a comment. NFC

By popular request, don't bother initializing a static pointer to NULL.

Use compile-time initialization for the list head, and make sure that
the sysctllog is also initialized before being used.

Define a new module class for the bufq_strategy modules. These need to
be loaded and intialized before autoconfigure runs, since some devices
(like disks and floppy drives) want to call bufq_alloc().

Modularize the various bufq strategies

branches: 1.21.6; 1.21.10;
Ensure that the top level sysctl nodes (kern, vfs, net, ...) exist before
the sysctl link sets are processed, and remove redundancy.

Shaves >13kB off of an amd64 GENERIC, not to mention >1k duplicate
lines of code.

branches: 1.20.12; 1.20.22; 1.20.26;
Provide unwind log for bufq sysctls, since (theoretically) bufq might
not be initialized during kernel bootstrap and therefore "permanent"
nodes can be created only with an unwind log.

Replace a large number of link set based sysctl node creations with
calls from subsystem constructors. Benefits both future kernel
modules and rump.

no change to sysctl nodes on i386/MONOLITHIC & build tested i386/ALL

malloc -> kmem_alloc

bufq_cancel: KNF.

g/c BUFQ_FOO() macros and use bufq_foo() directly.

branches: 1.15.8;
Add a BUFQ_CANCEL() next to BUFQ_PUT() and BUFQ_GET().

BUFQ_CANCEL(queue, element) removes the specified element previously queued
on the queue. It returns NULL if it was not found on the queue and the
element if it was successfully removed.

Run trough tech-kern and changed name from BUFQ_REVOKE() by suggestion of
Jason Thorpe.

Remove clause 3 and 4 from TNF licenses

branches: 1.13.26; 1.13.28; 1.13.30; 1.13.32;
It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

branches: 1.12.18; 1.12.32; 1.12.42;
- add ioctls to set/get disk bufq strategy.
- implement them for some drivers.

bufq_alloc: return correct errors rather than 0.

merge ktrace-lwp.

branches: 1.9.6;
bufq_alloc: fix BUFQ_STRAT_ANY. pointed by Juan RP.

sysctl_kern_bufq_strategies:
- handle too small buffer.
- handle the case that no bufq is configured.

sysctl_kern_bufq_strategies:
- don't assign size_t value to error number.
- remove an unnecessary assignment.

sysctl_kern_bufq_strategies: skip a dummy strategy correctly.

add some bufq helper functions.
#if 0'ed out as there is no user currently.

whitespace.

fix rcsid.

Add a sysctl function that will print all buffer queue strategies
built in the kernel:

$ sysctl kern.bufq.strategies
kern.bufq.strategies = disksort fcfs priocscan readprio
$

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

Fix a comment. NFC

By popular request, don't bother initializing a static pointer to NULL.

Use compile-time initialization for the list head, and make sure that
the sysctllog is also initialized before being used.

Define a new module class for the bufq_strategy modules. These need to
be loaded and intialized before autoconfigure runs, since some devices
(like disks and floppy drives) want to call bufq_alloc().

Modularize the various bufq strategies

branches: 1.21.6; 1.21.10;
Ensure that the top level sysctl nodes (kern, vfs, net, ...) exist before
the sysctl link sets are processed, and remove redundancy.

Shaves >13kB off of an amd64 GENERIC, not to mention >1k duplicate
lines of code.

branches: 1.20.12; 1.20.22; 1.20.26;
Provide unwind log for bufq sysctls, since (theoretically) bufq might
not be initialized during kernel bootstrap and therefore "permanent"
nodes can be created only with an unwind log.

Replace a large number of link set based sysctl node creations with
calls from subsystem constructors. Benefits both future kernel
modules and rump.

no change to sysctl nodes on i386/MONOLITHIC & build tested i386/ALL

malloc -> kmem_alloc

bufq_cancel: KNF.

g/c BUFQ_FOO() macros and use bufq_foo() directly.

branches: 1.15.8;
Add a BUFQ_CANCEL() next to BUFQ_PUT() and BUFQ_GET().

BUFQ_CANCEL(queue, element) removes the specified element previously queued
on the queue. It returns NULL if it was not found on the queue and the
element if it was successfully removed.

Run trough tech-kern and changed name from BUFQ_REVOKE() by suggestion of
Jason Thorpe.

Remove clause 3 and 4 from TNF licenses

branches: 1.13.26; 1.13.28; 1.13.30; 1.13.32;
It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

branches: 1.12.18; 1.12.32; 1.12.42;
- add ioctls to set/get disk bufq strategy.
- implement them for some drivers.

bufq_alloc: return correct errors rather than 0.

merge ktrace-lwp.

branches: 1.9.6;
bufq_alloc: fix BUFQ_STRAT_ANY. pointed by Juan RP.

sysctl_kern_bufq_strategies:
- handle too small buffer.
- handle the case that no bufq is configured.

sysctl_kern_bufq_strategies:
- don't assign size_t value to error number.
- remove an unnecessary assignment.

sysctl_kern_bufq_strategies: skip a dummy strategy correctly.

add some bufq helper functions.
#if 0'ed out as there is no user currently.

whitespace.

fix rcsid.

Add a sysctl function that will print all buffer queue strategies
built in the kernel:

$ sysctl kern.bufq.strategies
kern.bufq.strategies = disksort fcfs priocscan readprio
$

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)

By popular request, don't bother initializing a static pointer to NULL.

Use compile-time initialization for the list head, and make sure that
the sysctllog is also initialized before being used.

Define a new module class for the bufq_strategy modules. These need to
be loaded and intialized before autoconfigure runs, since some devices
(like disks and floppy drives) want to call bufq_alloc().

Modularize the various bufq strategies

branches: 1.21.6;
Ensure that the top level sysctl nodes (kern, vfs, net, ...) exist before
the sysctl link sets are processed, and remove redundancy.

Shaves >13kB off of an amd64 GENERIC, not to mention >1k duplicate
lines of code.

branches: 1.20.12; 1.20.22; 1.20.26;
Provide unwind log for bufq sysctls, since (theoretically) bufq might
not be initialized during kernel bootstrap and therefore "permanent"
nodes can be created only with an unwind log.

Replace a large number of link set based sysctl node creations with
calls from subsystem constructors. Benefits both future kernel
modules and rump.

no change to sysctl nodes on i386/MONOLITHIC & build tested i386/ALL

malloc -> kmem_alloc

bufq_cancel: KNF.

g/c BUFQ_FOO() macros and use bufq_foo() directly.

branches: 1.15.8;
Add a BUFQ_CANCEL() next to BUFQ_PUT() and BUFQ_GET().

BUFQ_CANCEL(queue, element) removes the specified element previously queued
on the queue. It returns NULL if it was not found on the queue and the
element if it was successfully removed.

Run trough tech-kern and changed name from BUFQ_REVOKE() by suggestion of
Jason Thorpe.

Remove clause 3 and 4 from TNF licenses

branches: 1.13.26; 1.13.28; 1.13.30; 1.13.32;
It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

branches: 1.12.18; 1.12.32; 1.12.42;
- add ioctls to set/get disk bufq strategy.
- implement them for some drivers.

bufq_alloc: return correct errors rather than 0.

merge ktrace-lwp.

branches: 1.9.6;
bufq_alloc: fix BUFQ_STRAT_ANY. pointed by Juan RP.

sysctl_kern_bufq_strategies:
- handle too small buffer.
- handle the case that no bufq is configured.

sysctl_kern_bufq_strategies:
- don't assign size_t value to error number.
- remove an unnecessary assignment.

sysctl_kern_bufq_strategies: skip a dummy strategy correctly.

add some bufq helper functions.
#if 0'ed out as there is no user currently.

whitespace.

fix rcsid.

Add a sysctl function that will print all buffer queue strategies
built in the kernel:

$ sysctl kern.bufq.strategies
kern.bufq.strategies = disksort fcfs priocscan readprio
$

- change the way to specify a bufq strategy. (by string rather than by number)
- rather than embedding bufq_state in driver softc,
have a pointer to the former.
- move bufq related functions from kern/subr_disk.c to kern/subr_bufq.c.
- rename method to strategy for consistency.
- move some definitions which don't need to be exposed to the rest of kernel
from sys/bufq.h to sys/bufq_impl.h.
(is it better to move it to kern/ or somewhere?)
- fix some obvious breakage in dev/qbus/ts.c. (not tested)