[ovs-dev] [RFC PATCH v2 6/7] flow: Split miniflow's map.

[Ben Pfaff]

On Fri, Jul 10, 2015 at 10:35:24AM -0700, Jarno Rajahalme wrote:
> Use two maps in miniflow to allow for expansion of struct flow past
> 512 bytes.  We now have one map for tunnel related fields, and another
> for the rest of the packet metadata and actual packet header fields.
> This split has the benefit that for non-tunneled packets the overhead
> should be minimal.
> 
> Some miniflow utilities now exist in two variants, new ones operating
> over all the data, and the old ones operating only on a single 64-bit
> map at a time.  The old ones require doubling of code but should
> execute faster, so those are used in the datapath and classifier's
> lookup path.
> 
> Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>

I get sparse warnings:

    ../lib/classifier-private.h:244:41: warning: shift too big (4294967258) for type unsigned long long
      CC       lib/flow.lo
      CC       lib/learn.lo
    ../lib/flow.c:461:9: warning: shift too big (98) for type unsigned long long
    ../lib/flow.c:461:9: warning: shift too big (4294967258) for type unsigned long long
    ../lib/flow.c:465:13: warning: shift too big (64) for type unsigned long long
    ../lib/flow.c:465:13: warning: shift too big (4294967262) for type unsigned long long

miniflow_get_map_in_range() is pretty big, though it should optimize
down a bit in particular cases.  Maybe you should mark it ALWAYS_INLINE
to help the compiler with that.

If you don't mind, I'd like to carefully review a v3 with the above
shifts fixed.