> > Let me just check that I understand the conditions under which this > occurs. When selecting unaligned mode, there is no check that the size > is divisible by the chunk_size as is the case in aligned mode. So we > can register a umem that is for example 15 4K pages plus 100 bytes and > in this case the second to last page will be marked as contiguous > (with the CONTIG_MASK) and a packet of length 300 starting at 15*4K - > 100 will be marked as valid even though it extends 100 bytes outside > the umem which ends at 15*4K + 100. Did I get this correctly? If so, > some more color in the commit message would be highly appreciated. Yes. You don't even need to cross the page. For example, if you have a packet length of 300 _within_ the final page then it could go past the end of the umem. In this case, the CONTIG_MASK would not even be looked at. The explanation is in the next commit message with the test. I will improve the commit message here though.
