similar to: [Patch] Remove unnecessary tlb flush in blktap_poll

include/xen/interface/io/ring.h uses full memory barriers to communicate with the other side. For guests compiled with CONFIG_SMP, smp_wmb and smp_mb would be sufficient, so mb() and wmb() here are only needed if a non-SMP guest runs on an SMP host. Switch to virt_xxx barriers which serve this exact purpose. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

include/xen/interface/io/ring.h uses full memory barriers to communicate with the other side. For guests compiled with CONFIG_SMP, smp_wmb and smp_mb would be sufficient, so mb() and wmb() here are only needed if a non-SMP guest runs on an SMP host. Switch to __smp_XXX barriers which serve this exact purpose. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. Introduce paravirtual versions of flush_tlb_multi() for KVM, Xen and hyper-v (Xen and hyper-v are only compile-tested). While the updated smp infrastructure is capable of running a function on a single local core, it is not optimized for this case. The multiple function

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. Introduce paravirtual versions of flush_tlb_multi() for KVM, Xen and hyper-v (Xen and hyper-v are only compile-tested). While the updated smp infrastructure is capable of running a function on a single local core, it is not optimized for this case. The multiple function

On 6/12/19 11:48 PM, Nadav Amit wrote: > To improve TLB shootdown performance, flush the remote and local TLBs > concurrently. Introduce flush_tlb_multi() that does so. The current > flush_tlb_others() interface is kept, since paravirtual interfaces need > to be adapted first before it can be removed. This is left for future > work. In such PV environments, TLB flushes are not

> On Jun 25, 2019, at 2:29 PM, Dave Hansen <dave.hansen at intel.com> wrote: > > On 6/12/19 11:48 PM, Nadav Amit wrote: >> To improve TLB shootdown performance, flush the remote and local TLBs >> concurrently. Introduce flush_tlb_multi() that does so. The current >> flush_tlb_others() interface is kept, since paravirtual interfaces need >> to be adapted

> On Jun 25, 2019, at 2:29 PM, Dave Hansen <dave.hansen at intel.com> wrote: > > On 6/12/19 11:48 PM, Nadav Amit wrote: >> To improve TLB shootdown performance, flush the remote and local TLBs >> concurrently. Introduce flush_tlb_multi() that does so. The current >> flush_tlb_others() interface is kept, since paravirtual interfaces need >> to be adapted

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

hi. trying to understand the idea behind _notify in #define RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(_r, _notify) do { \ RING_IDX __old = (_r)->sring->req_prod; \ RING_IDX __new = (_r)->req_prod_pvt; \ wmb(); /* back sees requests /before/ updated producer index */ \ (_r)->sring->req_prod = __new;

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

Signed-off-by: Jan Beulich <jbeulich@novell.com> Index: head-2007-02-27/drivers/char/mem.c =================================================================== --- head-2007-02-27.orig/drivers/char/mem.c 2007-03-05 10:00:18.000000000 +0100 +++ head-2007-02-27/drivers/char/mem.c 2007-02-27 16:27:37.000000000 +0100 @@ -787,7 +787,7 @@ static const struct file_operations mem_ .open =

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. The current flush_tlb_others() interface is kept, since paravirtual interfaces need to be adapted first before it can be removed. This is left for future work. In such PV environments, TLB flushes are not performed, at this time, concurrently. Add a static key to tell

Currently, local and remote TLB flushes are not performed concurrently, which introduces unnecessary overhead - each INVLPG can take 100s of cycles. This patch-set allows TLB flushes to be run concurrently: first request the remote CPUs to initiate the flush, then run it locally, and finally wait for the remote CPUs to finish their work. In addition, there are various small optimizations to avoid

[ Cover-letter is identical to v2, including benchmark results, excluding the change log. ] Currently, local and remote TLB flushes are not performed concurrently, which introduces unnecessary overhead - each INVLPG can take 100s of cycles. This patch-set allows TLB flushes to be run concurrently: first request the remote CPUs to initiate the flush, then run it locally, and finally wait for

This dependence is undesirable and logically incorrect. It''s undesirable because Xen network protocol should not depend on a OS-specific constant. It''s incorrect because the ring slots required doesn''t correspond to the number of frags a SKB has (consider compound page frags). This patch removes this dependence by correctly counting the ring slots required.

A buggy or malicious frontend should not be able to confuse netback. If we spot anything which is not as it should be then shutdown the device and don''t try to continue with the ring in a potentially hostile state. Well behaved and non-hostile frontends will not be penalised. As well as making the existing checks for such errors fatal also add a new check that ensures that there

add segring support in blkback Signed-off-by: Ronghui Duan <ronghui.duan@intel.com> diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index 45eda98..0bbc226 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -60,6 +60,10 @@ static int xen_blkif_reqs = 64; module_param_named(reqs, xen_blkif_reqs, int, 0);