mirror of https://gitee.com/openkylin/linux.git
f42a0fd13b
This change restricts the reading and setting of the head and tail pointers on 32bit X86 to 32bit for both correctness and performance reasons. On uniprocessor X86_32, the atomic64_read may be implemented as a non-locked cmpxchg8b. This may result in updates to the pointers done by the VMCI device being overwritten. On MP systems, there is no such correctness issue, but using 32bit atomics avoids the overhead of the locked 64bit operation. All this is safe because the queue size on 32bit systems will never exceed a 32bit value. Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com> Signed-off-by: Jorgen Hansen <jhansen@vmware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|---|---|---|
| .. | ||
| Kconfig | ||
| Makefile | ||
| vmci_context.c | ||
| vmci_context.h | ||
| vmci_datagram.c | ||
| vmci_datagram.h | ||
| vmci_doorbell.c | ||
| vmci_doorbell.h | ||
| vmci_driver.c | ||
| vmci_driver.h | ||
| vmci_event.c | ||
| vmci_event.h | ||
| vmci_guest.c | ||
| vmci_handle_array.c | ||
| vmci_handle_array.h | ||
| vmci_host.c | ||
| vmci_queue_pair.c | ||
| vmci_queue_pair.h | ||
| vmci_resource.c | ||
| vmci_resource.h | ||
| vmci_route.c | ||
| vmci_route.h | ||