Subject: Re: [RFC PATCH v2 tip 0/7] 64-bit BPF insn set and tracing filters

From: "H. Peter Anvin" <[email-masked]>
Date: Thu, 13 Feb 2014 14:32:25 -0800

On 02/06/2014 05:20 PM, Alexei Starovoitov wrote:
> 
> I believe that old BPF outlived itself and BPF64 should
> replace it in all current use cases plus a lot more.
> It just cannot happen at once.
> BPF64 can come in. bpf32->bpf64 converter functioning.
> JIT from bpf64->aarch64 and may be sparc64 needs to be in place.
> Then old bpf can fade away.
> 

I don't think that is doable any time soon.  Right now pretty much all
mobile devices, for example, are 32 bits and they really want to use
syscall filtering for security.  Performance matters greatly there.

As such, 32-bit JIT support is going to be very important for a long
time to come.

	-hpa