>Subject: Re: [PATCH rdma-next v4 10/12] RDMA/efa: Add EFA verbs
>implementation
>
>On 28-Mar-19 19:27, Jason Gunthorpe wrote:
>>>>> + unsigned long max_page_shift,
>>>>> + int *count, u8 *shift, u32 *ncont) {
>>>>> + unsigned long page_shift = umem->page_shift;
>>>>> + struct scatterlist *sg;
>>>>> + u64 base = ~0, p = 0;
>>>>> + unsigned long tmp;
>>>>> + unsigned long m;
>>>>> + u64 len, pfn;
>>>>> + int i = 0;
>>>>> + int entry;
>>>>> +
>>>>> + addr = addr >> page_shift;
>>>>> + tmp = (unsigned long)addr;
>>>>> + m = find_first_bit(&tmp, BITS_PER_LONG);
>>>>> + if (max_page_shift)
>>>>> + m = min_t(unsigned long, max_page_shift - page_shift, m);
>>>>> +
>>>>> + for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
>>>>> + len = sg_dma_len(sg) >> page_shift;
>>>>
>>>> Shouldn't assume the offset is zero here.
>>>
>>> Because elements are not necessarily PAGE_SIZE?
>>> If page combining is already done by ib_core, this whole function can
>>> probably be deleted.
>>
>> If you test and ack the patch above then page combining will be done
>> by the ib_core tomorrow :)
>>
>>>> This whole function should really better match what Shiraz is doing.
>>>> It looks like it is just ib_umem_find_single_pg_size() ??
>>>
>>> Yea, I think ib_umem_find_single_pg_size() could probably replace
>>> this whole function, this work isn't merged yet though right?
>>
>> Not yes, but if you test it and say it works and you need it, then it
>> can accelerate.
>
>Hey Shiraz and Jason -
>Looks like the last patchset that contains these new APIs
>(ib_umem_find_single_pg_size, return aligned memory blocks from SGL) was
>submitted around Feb 19 and got some comments.
>Should I wait for the new patches or cherry-pick v1? Sounds like the interface is
>going to change, not sure if I should rebase the driver on top of that.
Hi Gal - Sorry for the delayed response. Looks like you already tested the page combining
patch. Thanks! :)
Additionally, if you want to try out the API to find the best driver supported page size in the MR
(ib_umem_find_single_pg_size()) and see if it fits your need, then you can grab that patch
from v1 patchset. I don’t intend to update this API (well maybe a naming change).
So you probably want to cherry-pick this one on top of the page combining patch.
[v1 2/6] RDMA/umem: Add API to find best driver supported page size in an MR]
https://patchwork.kernel.org/patch/10819995/
The iterator that returns aligned memory blocks
[v1 3/6 RDMA/umem: Add API to return aligned memory blocks from SGL]
is undergoing a re-spin and is not ready.
Shiraz
