Messages in this thread | | | Subject | Re: [PATCH net-next V4 5/5] vhost: access vq metadata through kernel virtual address | From | Jason Wang <> | Date | Fri, 25 Jan 2019 17:16:32 +0800 |
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On 2019/1/25 上午11:00, Michael S. Tsirkin wrote: > On Thu, Jan 24, 2019 at 12:07:54PM +0800, Jason Wang wrote: >>> Meanwhile, could you pls post data comparing this last patch with the >>> below? This removes the speculation barrier replacing it with a >>> (useless but at least more lightweight) data dependency. >> SMAP off >> >> Your patch: 7.2MPPs >> >> vmap: 7.4Mpps > OK so while we keep looking into vmap, why don't we merge something like > the below? Seems quite straight forward ... >
The problem is it gives ~8% regression on PPS when SMAP is on. This is probably because the latency of lfence is hided by previous stac as mentioned in the commit b3bbfb3fb5d25776b8e3f361d2eedaabb0b496cd.
Thanks
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