Re: [ovs-dev] [PATCH] datapath: Use u64_stats_sync for datapath and vport stats.

2011-11-21 Thread Jesse Gross
On Mon, Nov 21, 2011 at 9:49 AM, Ben Pfaff wrote: > On Sat, Nov 19, 2011 at 10:20:24AM -0800, Jesse Gross wrote: >> We currently use a seqcount to prevent reading partial 64-bit stats >> on 32-bit CPUs.  u64_stats_sync uses the same logic but elides it on >> 64-bit and uniprocessor machines.  This

Re: [ovs-dev] [PATCH] datapath: Use u64_stats_sync for datapath and vport stats.

2011-11-21 Thread Ben Pfaff
On Sat, Nov 19, 2011 at 10:20:24AM -0800, Jesse Gross wrote: > We currently use a seqcount to prevent reading partial 64-bit stats > on 32-bit CPUs. u64_stats_sync uses the same logic but elides it on > 64-bit and uniprocessor machines. This improves performance (primarily > on non-x86 architectu

[ovs-dev] [PATCH] datapath: Use u64_stats_sync for datapath and vport stats.

2011-11-19 Thread Jesse Gross
We currently use a seqcount to prevent reading partial 64-bit stats on 32-bit CPUs. u64_stats_sync uses the same logic but elides it on 64-bit and uniprocessor machines. This improves performance (primarily on non-x86 architectures) at the cost of not guaranteeing that packet and byte counts were