Martin Schwidefsky
ef6edc9746
[PATCH] Directed yield: cpu_relax variants for spinlocks and rw-locks ...
On systems running with virtual cpus there is optimization potential in
regard to spinlocks and rw-locks. If the virtual cpu that has taken a lock
is known to a cpu that wants to acquire the same lock it is beneficial to
yield the timeslice of the virtual cpu in favour of the cpu that has the
lock (directed yield).
With CONFIG_PREEMPT="n" this can be implemented by the architecture without
common code changes. Powerpc already does this.
With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
_raw_read_trylock and _raw_write_trylock in kernel/spinlock.c. If the lock
could not be taken cpu_relax is called. A directed yield is not possible
because cpu_relax doesn't know anything about the lock. To be able to
yield the lock in favour of the current lock holder variants of cpu_relax
for spinlocks and rw-locks are needed. The new _raw_spin_relax,
_raw_read_relax and _raw_write_relax primitives differ from cpu_relax
insofar that they have an argument: a pointer to the lock structure.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01 00:39:21 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] powerpc: Unify udbg ( #2 )
2006-01-09 14:49:54 +11:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2006-05-06 19:59:18 +01:00
[PATCH] ppc32: board-specific part of fs_enet update
2006-08-19 17:44:31 -04:00
[PATCH] irq-flags: PPC: Use the new IRQF_ constants
2006-07-02 13:58:48 -07:00
[PATCH] powerpc: trivial: modify comments to refer to new location of files
2006-02-10 16:53:51 +11:00
[PATCH] #elif that should've been #elif defined
2006-09-23 11:34:43 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] ppc32: remove "jumbo" member from ocp_func_emac_data
2006-01-06 08:33:30 -08:00
[PATCH] Update email address for Kumar
2005-11-13 18:14:10 -08:00
[POWERPC] convert string i/o operations to C
2006-09-20 14:06:18 +10:00
[PATCH] ppc: Fix ARCH=ppc build with xmon
2005-11-08 11:19:48 +11:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
2006-06-22 22:11:30 -07:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
2006-06-22 22:11:30 -07:00
[PATCH] ppc32: board-specific part of fs_enet update
2006-08-19 17:44:31 -04:00
[PATCH] powerpc: trivial: modify comments to refer to new location of files
2006-02-10 16:53:51 +11:00
[PATCH] ppc32: Reorganize and complete MPC52xx initial cpu setup
2006-03-27 14:49:00 +11:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
2006-06-22 22:11:30 -07:00
[PATCH] ppc32: board-specific part of fs_enet update
2006-08-19 17:44:31 -04:00
[POWERPC] remove unused io accessors
2006-09-20 14:06:17 +10:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] ppc32: mv64x60 updates & enhancements
2005-09-05 00:06:00 -07:00
[PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree
2006-06-26 12:25:08 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
typo fixes: mecanism -> mechanism
2006-06-30 18:20:44 +02:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] powerpc: pci_address_to_pio fix
2006-01-09 15:05:56 +11:00
[PATCH] 64bit resource: change pci core and arch code to use resource_size_t
2006-06-27 09:24:00 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] Standardize pxx_page macros
2006-09-26 08:48:51 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] ppc32: odd fixes and improvements in ppc_sys
2006-04-28 21:05:16 +10:00
[PATCH] ppc32: cleanup AMCC PPC40x eval boards to support U-Boot
2005-11-07 07:53:26 -08:00
ppc: Remove CHRP, POWER3 and POWER4 support from arch/ppc
2006-03-28 10:22:10 +11:00
[POWERPC] 40x: Fix debug status register defines
2006-09-21 22:59:39 +10:00
[PATCH] RapidIO support: ppc32
2005-11-07 07:53:47 -08:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] Directed yield: cpu_relax variants for spinlocks and rw-locks
2006-10-01 00:39:21 -07:00
[PATCH] remove set_wmb - arch removal
2006-07-14 21:56:14 -07:00
Don't include linux/config.h from anywhere else in include/
2006-04-26 12:56:16 +01:00
[PATCH] powerpc: trivial: modify comments to refer to new location of files
2006-02-10 16:53:51 +11:00
ef6edc9746