Re: [Xen-devel] [PATCH 1/3] x86/pv: Avoid locked bit manipulation in register_guest_callback()

2018-03-20 Thread Roger Pau Monné
On Thu, Mar 15, 2018 at 11:58:40AM +, Andrew Cooper wrote: > Changes to arch.vgc_flags are made to current in syncrhonous context only, and > don't need to be locked. (The only other changes are via > arch_set_info_guest(), which operates on descheduled vcpus only). > > Replace the

Re: [Xen-devel] [PATCH 1/3] x86/pv: Avoid locked bit manipulation in register_guest_callback()

2018-03-19 Thread Jan Beulich
>>> On 15.03.18 at 12:58, wrote: > Changes to arch.vgc_flags are made to current in syncrhonous context only, and > don't need to be locked. (The only other changes are via > arch_set_info_guest(), which operates on descheduled vcpus only). > > Replace the

[Xen-devel] [PATCH 1/3] x86/pv: Avoid locked bit manipulation in register_guest_callback()

2018-03-15 Thread Andrew Cooper
Changes to arch.vgc_flags are made to current in syncrhonous context only, and don't need to be locked. (The only other changes are via arch_set_info_guest(), which operates on descheduled vcpus only). Replace the {set,clear}_bit() calls with compiler-visible bitwise operations. Signed-off-by: