b6be31c7ca
illumos/illumos-gate@8b65a70b76
8b65a70b76
https://www.illumos.org/issues/7541
When calling zpool import, zpool does a few ioctls to ZFS.
zpool allocates a buffer in userland and passes it to the kernel so that ZFS
can copy info into it. ZFS will use it to put the nvlist that describes the
pool configuration.
If the allocated buffer is too small, ZFS will return ENOMEM and the call will
have to be redone. This wastes CPU time and slows down the import process. This
happens very often for the ZFS_IOC_POOL_TRYIMPORT call.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>
Author: Pavel Zakharov <pavel.zakharov@delphix.com>
MFC after: 2 weeks