On Fri, May 8, 2020 at 9:43 AM Kevin Hao <haoke...@gmail.com> wrote: > > In the current codes, the octeontx2 uses its own method to allocate > the pool buffers, but there are some issues in this implementation. > 1. We have to run the otx2_get_page() for each allocation cycle and > this is pretty error prone. As I can see there is no invocation > of the otx2_get_page() in otx2_pool_refill_task(), this will leave > the allocated pages have the wrong refcount and may be freed wrongly.
Thanks for pointing, will fix. > 2. It wastes memory. For example, if we only receive one packet in a > NAPI RX cycle, and then allocate a 2K buffer with otx2_alloc_rbuf() > to refill the pool buffers and leave the remain area of the allocated > page wasted. On a kernel with 64K page, 62K area is wasted. > > IMHO it is really unnecessary to implement our own method for the > buffers allocate, we can reuse the napi_alloc_frag() to simplify > our code. > > Signed-off-by: Kevin Hao <haoke...@gmail.com> Have you measured performance with and without your patch ? I didn't use napi_alloc_frag() as it's too costly, if in one NAPI instance driver receives 32 pkts, then 32 calls to napi_alloc_frag() and updates to page ref count per fragment etc are costly. When traffic rate is less then it may not matter much. Thanks, Sunil.
