2018-04-23 18:18 GMT+02:00 Michael S. Tsirkin <m...@redhat.com>:
[...]
>> +static void xdp_umem_unpin_pages(struct xdp_umem *umem)
>> +{
>> + unsigned int i;
>> +
>> + if (umem->pgs) {
>> + for (i = 0; i < umem->npgs; i++)
>
> Since you pin them with FOLL_WRITE, I assume these pages
> are written to.
> Don't you need set_page_dirty_lock here?
>
Hmm, I actually *removed* it from the RFC V2, but after doing some
homework, I think you're right. Thanks for pointing this out!
Thinking more about this; This function is called from sk_destruct,
and in the Tx case the sk_destruct can be called from interrupt
context, where set_page_dirty_lock cannot be called.
Are there any preferred ways of solving this? Scheduling the whole
xsk_destruct call to a workqueue is one way (I think). Any
cleaner/better way?
[...]
>> +static int __xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
>> +{
>> + u32 frame_size = mr->frame_size, frame_headroom = mr->frame_headroom;
>> + u64 addr = mr->addr, size = mr->len;
>> + unsigned int nframes;
>> + int size_chk, err;
>> +
>> + if (frame_size < XDP_UMEM_MIN_FRAME_SIZE || frame_size > PAGE_SIZE) {
>> + /* Strictly speaking we could support this, if:
>> + * - huge pages, or*
>
> what does "or*" here mean?
>
Oops, I'll change to just 'or' in the next revision.
Thanks!
Björn
