Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-17 Thread Yan Vugenfirer
On Mar 17, 2014, at 8:43 AM, Ronen Hod wrote: > On 03/13/2014 09:28 AM, Jason Wang wrote: >> On 03/10/2014 04:03 PM, Michael S. Tsirkin wrote: >>> On Fri, Mar 07, 2014 at 01:28:27PM +0800, Jason Wang wrote: > We used to stop the handling of tx when the number of pending DMAs > exceeds VH

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-16 Thread Ronen Hod
On 03/13/2014 09:28 AM, Jason Wang wrote: On 03/10/2014 04:03 PM, Michael S. Tsirkin wrote: On Fri, Mar 07, 2014 at 01:28:27PM +0800, Jason Wang wrote: We used to stop the handling of tx when the number of pending DMAs exceeds VHOST_MAX_PEND. This is used to reduce the memory occupation of both

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-13 Thread Jason Wang
On 03/10/2014 04:03 PM, Michael S. Tsirkin wrote: > On Fri, Mar 07, 2014 at 01:28:27PM +0800, Jason Wang wrote: >> > We used to stop the handling of tx when the number of pending DMAs >> > exceeds VHOST_MAX_PEND. This is used to reduce the memory occupation >> > of both host and guest. But it was t

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-10 Thread Michael S. Tsirkin
On Fri, Mar 07, 2014 at 01:28:27PM +0800, Jason Wang wrote: > We used to stop the handling of tx when the number of pending DMAs > exceeds VHOST_MAX_PEND. This is used to reduce the memory occupation > of both host and guest. But it was too aggressive in some cases, since > any delay or blocking of

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-09 Thread Jason Wang
On 03/08/2014 05:39 AM, David Miller wrote: > From: Jason Wang > Date: Fri, 7 Mar 2014 13:28:27 +0800 > >> This is because the delay added by htb may lead the delay the finish >> of DMAs and cause the pending DMAs for tap0 exceeds the limit >> (VHOST_MAX_PEND). In this case vhost stop handling tx

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-09 Thread Qin Chuanyu
On 2014/3/7 13:28, Jason Wang wrote: We used to stop the handling of tx when the number of pending DMAs exceeds VHOST_MAX_PEND. This is used to reduce the memory occupation of both host and guest. But it was too aggressive in some cases, since any delay or blocking of a single packet may delay or

Re: [PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-07 Thread David Miller
From: Jason Wang Date: Fri, 7 Mar 2014 13:28:27 +0800 > This is because the delay added by htb may lead the delay the finish > of DMAs and cause the pending DMAs for tap0 exceeds the limit > (VHOST_MAX_PEND). In this case vhost stop handling tx request until > htb send some packets. The problem

[PATCH net V2] vhost: net: switch to use data copy if pending DMAs exceed the limit

2014-03-06 Thread Jason Wang
We used to stop the handling of tx when the number of pending DMAs exceeds VHOST_MAX_PEND. This is used to reduce the memory occupation of both host and guest. But it was too aggressive in some cases, since any delay or blocking of a single packet may delay or block the guest transmission. Consider