On 26/05/15 12:19, Bala Manoharan wrote:
In the current API the odp_packet_alloc() function always takes "len"
as input parameter and hence it is not required to support any default
size.
Yes, that's why I think it's a problem that linux-generic takes 0 as
"use the segment size of the pool", whilst another implementation (e.g.
ODP-DPDK) can interpret it as a buffer with only (default) headroom and
tailroom. I think my interpretation for ODP-DPDK is more logical, but
it's not necessarily what we need. We should probably define that in the
API.
In case of odp_buffer_alloc() the default value of allocation will be
equal to the "size" parameter which will be the value given during
odp_pool_create() function as part of odp_pool_params_t variable.
Yes, but when you create a packet pool, you'll set up the "pkt" part of
that union, so buf.size could be anything. It's just a coincidence that
it's pkt.len, odp_buffer_alloc() uses the wrong value there. The same
problem applies to odp_packet_alloc(), it also uses buf.size
If this value is given as "0" then the HW will chose the default
segment size supported by the HW.
This value will be the value of the segment with which the pools are
getting created by default in the HW.
odp_pool_create just copies the parameters, it doesn't modify them to
reflect what values were used in the end. So odp_buffer_alloc() will
call buffer_alloc() with s.params.buf.size, and if that's 0, "totsize =
pool->s.headroom + size + pool->s.tailroom".
Zoli
Regards,
Bala
On 26 May 2015 at 16:25, Zoltan Kiss <[email protected]> wrote:
Which value? I've mentioned seg_len and seg_size, but the latter actually
doesn't exist. I guess I meant 'len'. The trouble with them, that you can
set both of them to 0 to ask for the default, so even if you look up the
params with odp_pool_info(), you can end up with both values 0.
So how do you figure out what length should be used by odp_buffer_alloc?
With the current API definition it will probably end up using pkt.len, just
by accident.
And the same applies to odp_packet_alloc, although I think it's also a bug
that when the user requested a 0 length buffer (plus headroom and tailroom),
it gets one with the default values.
Zoli
On 23/05/15 03:00, Bill Fischofer wrote:
In linux-generic that value represents the default allocation length.
On Friday, May 22, 2015, Zoltan Kiss <[email protected]
<mailto:[email protected]>> wrote:
Hi,
While fixing up things in the DPDK implementation I've found that
linux-generic might have some troubles too. odp_buffer_alloc() and
odp_packet_alloc() uses
odp_pool_to_entry(pool_hdl)->s.params.buf.size, but if it's a packet
pool (which is always true in case of odp_packet_alloc(), and might
be true with odp_buffer_alloc()).
My first idea would be to use s.params.pkt.seg_len in that case, but
it might be 0. Maybe s.seg_size would be the right value?
If anyone has time to come up with a patch to fix this, feel free, I
probably won't have time to work on this in the near future.
Zoli
_______________________________________________
lng-odp mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/lng-odp
_______________________________________________
lng-odp mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/lng-odp
_______________________________________________
lng-odp mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/lng-odp
