K 10
svn:author
V 7
asomers
K 8
svn:date
V 27
2017-10-23T23:12:01.460476Z
K 7
svn:log
V 1072
Remove artificial restriction on lio_listio's operation count

In r322258 I made p1003_1b.aio_listio_max a tunable. However, further
investigation shows that there was never any good reason for that limit to
exist in the first place. It's used in two completely different ways:

* To size a UMA zone, which globally limits the number of concurrent
  aio_suspend calls.

* To artifically limit the number of operations in a single lio_listio call.
  There doesn't seem to be any memory allocation associated with this limit.

This change does two things:

* Properly names aio_suspend's UMA zone, and sizes it based on a new constant.

* Eliminates the artifical restriction on lio_listio. Instead, lio_listio
  calls will now be limited by the more generous max_aio_queue_per_proc. The
  old p1003_1b.aio_listio_max is now an alias for
  vfs.aio.max_aio_queue_per_proc, so sysconf(3) will still work with
  _SC_AIO_LISTIO_MAX.

Reported by:	bde
Reviewed by:	jhb
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D12120

END