ia64/xen-unstable

changeset 11681:0c29e0d1c67b

[BLKTAP] Remove unnecessary TLB flush from blktap driver.

blktap_poll is calling tlb_flush_all() in its main ring buffer polling
loop. This seems to be superfluous: the hypervisor should be
performing
any necessary tlb flushes on grant table operations performed by the
back-end. Even a simple memory barrier is unnecessary here as the
RING_PUSH_REQUESTS() call performs a wmb() anyway.

And tlb_flush_all() is not exported to modules, so this call prevents
blktap from building as a module. Just remove it.

Signed-off-by: Stephen Tweedie <sct@redhat.com>
author kfraser@localhost.localdomain
date Fri Sep 29 11:17:29 2006 +0100 (2006-09-29)
parents 16759bdbd6c2
children dea06c7fd19d
files linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c
line diff
     1.1 --- a/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c	Fri Sep 29 11:16:52 2006 +0100
     1.2 +++ b/linux-2.6-xen-sparse/drivers/xen/blktap/blktap.c	Fri Sep 29 11:17:29 2006 +0100
     1.3 @@ -692,7 +692,6 @@ static unsigned int blktap_poll(struct f
     1.4  
     1.5  	poll_wait(filp, &info->wait, wait);
     1.6  	if (info->ufe_ring.req_prod_pvt != info->ufe_ring.sring->req_prod) {
     1.7 -		flush_tlb_all();
     1.8  		RING_PUSH_REQUESTS(&info->ufe_ring);
     1.9  		return POLLIN | POLLRDNORM;
    1.10  	}