Commit Graph

3 Commits

Author SHA1 Message Date
Mark Johnston
fdcb79b52e
spl: Don't check FreeBSD rwlocks for double initialization (#13019)
This checking breaks KMSAN since it effectively loads from uninitialized
memory to see if the lock is already initialized.  This happens in
dnode_cons() for example.  This checking is not very useful, partly due
to UMA's memory trashing, and is already disabled for mutexes.  Make
mutexes and rwlocks consistent: remove double-initialization checking
for rwlocks, and pass SX_NEW to disable the same checking in
lock_init().

No functional change intended, this affects only debug builds.

As a side note, kmem cache constructors/destructors are implemented
suboptimally on FreeBSD.  FreeBSD's slab allocator, UMA, supports two
pairs of constructors/destructors: ctor/dtor and init/fini.  The former
are called upon every allocation and free of an item, while the latter
are called when an item is imported or released from a zone,
respectively.  That is, when a slab is allocated to a particular cache,
it is subdivided into items, and init is called on each.  fini is called
when the slab is being prepared to be freed back to the system.  The
intent is for them to initialize static fields such as locks, which
do not need to be initialized upon each allocation of an item.

In illumos, kmem_cache constructors/destructors correspond to UMA's
init/fini callbacks.  However, in the SPL they are implemented as UMA
ctor/dtors, meaning that they get called far more often than necessary.
This may be difficult to fix, since new code may assume the kmem cache
ctor/dtors are in fact called upon each allocation/free, and there
doesn't seem to be a clear way to implement the intended semantics on
Linux.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Mark Johnston <markj@FreeBSD.org>
Closes #13019
2022-01-31 10:58:45 -08:00
наб
7ada752a93 Clean up CSTYLEDs
69 CSTYLED BEGINs remain, appx. 30 of which can be removed if cstyle(1)
had a useful policy regarding
  CALL(ARG1,
  	ARG2,
  	ARG3);
above 2 lines. As it stands, it spits out *both*
  sysctl_os.c: 385: continuation line should be indented by 4 spaces
  sysctl_os.c: 385: indent by spaces instead of tabs
which is very cool

Another >10 could be fixed by removing "ulong" &al. handling.
I don't foresee anyone actually using it intentionally
(does it even exist in modern headers? why did it in the first place?).

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12993
2022-01-26 11:38:52 -08:00
Matthew Macy
9f0a21e641
Add FreeBSD support to OpenZFS
Add the FreeBSD platform code to the OpenZFS repository.  As of this
commit the source can be compiled and tested on FreeBSD 11 and 12.
Subsequent commits are now required to compile on FreeBSD and Linux.
Additionally, they must pass the ZFS Test Suite on FreeBSD which is
being run by the CI.  As of this commit 1230 tests pass on FreeBSD
and there are no unexpected failures.

Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #898 
Closes #8987
2020-04-14 11:36:28 -07:00