Module Name: src
Committed By: riastradh
Date: Wed Aug 9 08:38:47 UTC 2023
Modified Files:
src/sys/arch/xen/xen: xennetback_xenbus.c
Log Message:
xvif(4): Omit needless membars in xennetback_rx_copy_process.
- No need for barrier around touching req_cons and rsp_prod_pvt,
which are private.
- RING_PUSH_RESPONSES_AND_CHECK_NOTIFY updates the shared req_prod and
then issues xen_mb, which is all that we need between the update of
shared req_prod and hypervisor_notify_via_evtchn.
(Between updating the shared req_prod and issuing
hypervisor_notify_via_evtchn, only xen_wmb is needed. But after
writing to the shared req_prod, RING_PUSH_REQUESTS_AND_CHECK_NOTIFY
must also read from the shared rsp_event, which requires the
store-before-load ordering that only xen_mb provides.)
To generate a diff of this commit:
cvs rdiff -u -r1.121 -r1.122 src/sys/arch/xen/xen/xennetback_xenbus.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
