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Re: [XENVBD PATCH 3/3] ring: Weaken and delete unnecessary barriers
- To: Tu Dinh <ngoc-tu.dinh@xxxxxxxxxx>, "win-pv-devel@xxxxxxxxxxxxxxxxxxxx" <win-pv-devel@xxxxxxxxxxxxxxxxxxxx>
- From: Owen Smith <owen.smith@xxxxxxxxxx>
- Date: Wed, 20 May 2026 08:35:52 +0000
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- Thread-topic: [XENVBD PATCH 3/3] ring: Weaken and delete unnecessary barriers
While there is potentially a difference between xen_rmb() and xen_wmb() in
Linux, both
are defined as KeMemoryBarrierWithoutFence() in the Windows drivers.
Is it necessary to have both entries here?
I take it that using xen_mb() (i.e. KeMemoryBarrier()) is not required, and a
single
KeMemoryBarrierWithoutFence() should be sufficient
Owen
@@ -1260,7 +1260,8 @@ BlkifRingPoll(
Retry = TRUE;
}
- KeMemoryBarrier();
+ xen_rmb();
+ xen_wmb();
BlkifRing->Front.rsp_cons = rsp_cons;
BlkifRing->Shared->rsp_event = rsp_cons + 1;
|
