Fix slow uthread context switches
authorBarret Rhoden <brho@cs.berkeley.edu>
Tue, 8 Nov 2016 16:16:44 +0000 (11:16 -0500)
committerBarret Rhoden <brho@cs.berkeley.edu>
Tue, 29 Nov 2016 16:19:36 +0000 (11:19 -0500)
commite6870388fc57727bd93a2c1f672dcaa3d3638db2
tree10e5abfa8f821f2a41af316a796ada059cb2e3b3
parent8e8ba99bcd34b8ba78e886c39bb20c3bc55f2397
Fix slow uthread context switches

The lock addq is accessing 8 bytes, but we only need to access one byte.
Accessing 8 bytes could span a cacheline boundary, which it does currently.
Doing so causes two cache misses!

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
user/parlib/x86/vcore.c