exec: avoid unnecessary cacheline bounce on ram_list.mru_block
authorPaolo Bonzini <pbonzini@redhat.com>
Thu, 22 Oct 2015 11:51:30 +0000 (13:51 +0200)
committerMichael Tokarev <mjt@tls.msk.ru>
Fri, 6 Nov 2015 12:42:38 +0000 (15:42 +0300)
commit68851b98e5bf6d397498b74f1776801274ab8d48
treed773342247525f12874ae07ef39844bf2dd24558
parent74de807f794ac5201b2b3c38ddadeef84a676a97
exec: avoid unnecessary cacheline bounce on ram_list.mru_block

Whenever the MRU cache hits for the list of RAM blocks, qemu_get_ram_block
does an unnecessary write that causes a processor cache line to bounce
from one core to another.  This causes a performance hit.

Reported-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
exec.c