lkml.org 
[lkml]   [2017]   [Apr]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH RFC 5/6] KVM: mark requests that do not need a wakeup
From
Date
On 06/04/17 21:20, Radim Krčmář wrote:
> Some operations must ensure that the guest is not running with stale
> data, but if the guest is halted, then the update can wait until another
> event happens. kvm_make_all_requests() currently doesn't wake up, so we
> can mark all requests used with it.
>
> First 8 bits were arbitrarily reserved for request numbers.
>
> Most uses of requests have the request type as a constant, so a compiler
> will optimize the '&'.
>
> An alternative would be to have an inline function that would return
> whether the request needs a wake-up or not, but I like this one better
> even though it might produce worse assembly.
>
> Suggested-by: Christoffer Dall <cdall@linaro.org>
> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
> ---
> Btw. do you recall which macro allowed to define bitmasks? (It has
> two arguments, FROM and TO.)

GENMASK (and its _ULL variant), defined in include/linux/bitops.h.

Thanks,

M.
--
Jazz is not dead. It just smells funny...

\
 
 \ /
  Last update: 2017-04-07 10:28    [W:0.152 / U:0.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site