[dpdk-dev] [PATCH v2 0/3] net: fix out of order Rx read issue

2016-10-19 Thread Bruce Richardson
On Tue, Oct 18, 2016 at 11:33:43AM +, Ananyev, Konstantin wrote: > > > > > > In vPMD, when load Rx desc with _mm_loadu_si128, > > volatile point will be cast into non-volatile point. > > So GCC is allowed to reorder the load instructions, > > while Rx read's correctness is reply on these loa

[dpdk-dev] [PATCH v2 0/3] net: fix out of order Rx read issue

2016-10-18 Thread Ananyev, Konstantin
> > In vPMD, when load Rx desc with _mm_loadu_si128, > volatile point will be cast into non-volatile point. > So GCC is allowed to reorder the load instructions, > while Rx read's correctness is reply on these load > instructions to follow a backward sequence strictly, > so we add compile barrie

[dpdk-dev] [PATCH v2 0/3] net: fix out of order Rx read issue

2016-10-18 Thread Qi Zhang
In vPMD, when load Rx desc with _mm_loadu_si128, volatile point will be cast into non-volatile point. So GCC is allowed to reorder the load instructions, while Rx read's correctness is reply on these load instructions to follow a backward sequence strictly, so we add compile barrier to prevent