Resending due to plain-text email issue that caused mailing list to get skipped.
Thank you for the feedback. I agree with you and would prefer to use
bytes/kbytes. Here are the 2 concerns that led to me keeping it as
pages:
1. Reduce the impact of the patch. Here is the call trace to reach the
failure warning:
<… usual mmap() stuff …>
mmap_region() -> security_enough_memory_mm() -> __vm_enough_memory()
Within mmap_region(), the length variable originally passed to mmap()
gets right-shifted to get the page count. My first thought was to add
an additional an additional argument to security_enough_memory_mm() of
type unsigned long to keep that variable, but saw a handful of calls
to it that would have to conform to the change. Not that I do not
think this debug statement does not warrant that, I felt the less
impact, the better.
2. Concerned about losing bits. When converting back to bytes I was
worried about the loss of precision and printing that number back to
users:
unsigned long bytes_failed = pages << (PAGE_SHIFT);