freebsd-dev/sys/cddl
Alexander Motin 904eaff3f7 MFV r337210: 9577 remove zfs_dbuf_evict_key tsd
The zfs_dbuf_evict_key TSD (thread-specific data) is not necessary - we can
instead pass a flag down in a few places to prevent recursive dbuf eviction.
Making this change has 3 benefits:

1. The code semantics are easier to understand.
2. On Linux, performance is improved, because creating/removing TSD values
(by setting to NULL vs non-NULL) is expensive, and we do it very often.
3. According to Nexenta, the current semantics can cause a deadlock when
concurrently calling dmu_objset_evict_dbufs() (which is rare today, but they
are working on a "parallel unmount" change that triggers this more easily)

illumos/illumos-gate@c2919acbea

Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Richard Lowe <richlowe@richlowe.net>
Author:     Matthew Ahrens <mahrens@delphix.com>
2018-08-03 00:01:48 +00:00
..
boot/zfs Mark two things as unused (since they are only sometimes used) and 2017-12-03 04:55:33 +00:00
compat/opensolaris opensolaris compat: fix compile error 2018-07-03 23:45:02 +00:00
contrib/opensolaris MFV r337210: 9577 remove zfs_dbuf_evict_key tsd 2018-08-03 00:01:48 +00:00
dev dtrace/powerpc: Correct register indices for non-indexed registers in the trapframe 2018-07-16 19:47:29 +00:00