8efcbab674
Implement a version of the old spinlock algorithm, in which everyone spins waiting for a lock byte. In order to be compatible with the ticket-lock's use of a zero initializer, this uses the convention of '0' for unlocked and '1' for locked. This algorithm is much better than ticket locks in a virtual envionment, because it doesn't interact badly with the vcpu scheduler. If there are multiple vcpus spinning on a lock and the lock is released, the next vcpu to be scheduled will take the lock, rather than cycling around until the next ticketed vcpu gets it. To use this, you must call paravirt_use_bytelocks() very early, before any spinlocks have been taken. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Christoph Lameter <clameter@linux-foundation.org> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Virtualization <virtualization@lists.linux-foundation.org> Cc: Xen devel <xen-devel@lists.xensource.com> Cc: Thomas Friebel <thomas.friebel@amd.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu> |
||
|---|---|---|
| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| ia32 | ||
| kernel | ||
| kvm | ||
| lguest | ||
| lib | ||
| mach-default | ||
| mach-es7000 | ||
| mach-generic | ||
| mach-rdc321x | ||
| mach-voyager | ||
| math-emu | ||
| mm | ||
| oprofile | ||
| pci | ||
| power | ||
| vdso | ||
| video | ||
| xen | ||
| Kconfig | ||
| Kconfig.cpu | ||
| Kconfig.debug | ||
| Makefile | ||
| Makefile_32.cpu | ||