This particular program attempts to use the TSC to measure how long
certainly libpmc operations take. Depending on the quality of
the rdtsc() macro on a particular architecture this may work
more or less well.
* Implements Start Stop Unit for SATA direct-attach devices in IR mode to avoid
data corruption.
* Use CAM_DEV_NOT_THERE instead of CAM_SEL_TIMEOUT and CAM_TID_INVALID
Obtained from: LSI
MFC after: 2 weeks
to counteract the default behaviour of always trying each and every
file system until one succeeds, or the open fails. The problem with the
loader is that we've implemented features based on this behavior. The
handling of compressed files is a good example of this. However, it is
in general highly undesirable to not have a one-time probe (or taste
in the geom lingo), followed by something similar to a mount whenever
we (first) read from a device. Everytime we go to the same device, we
can reasonably assume it (still) has the same file system. For file
systems that need to do far more that a trivial read of a super block,
not having something similar to a mount operation is disastrous from
a performance (and thus usability) perspective.
But, again, since we've implemented features based on this stateless
approach, things can get complicated quickly if and when we want to
change this. And yet, we sometimes do need stateful behaviour.
For this reason, this change simply introduces exclusive_file_system.
When set to the fsops of the file system to use, the open call will
only try this file system. Setting it to NULL restores the default
behaviour. It's a low-cost (low-brow?) approach to provide enough
control without re-implementing the guts of the loader.
A good example of when this is useful is when we're trying to load
files out of a container (say, a software packaga) that itself lives
on a file system or is fetched over the network. While opening the
container can be done in the normal stateless manner, once it is
opened, subsequent opens should only consider the container.
Obtained from: Juniper Networks, Inc.
restore was failing because ZFS was reporting a blocksize that was
not a multiple of 1024. Replace restore's failed assertion with
code that writes restored files in a blocksize that works for
restore (a multiple of 1024) despite being non-optimal for ZFS.
Submitted by: Dmitry Morozovsky
Tested by: Dmitry Morozovsky
MFC after: 1 week
features. If bootverbose is enabled, a detailed list is provided;
otherwise, a single-line summary is displayed.
- Add read-only sysctls for optional VT-x capabilities used by bhyve
under a new hw.vmm.vmx.cap node. Move a few exiting sysctls that
indicate the presence of optional capabilities under this node.
CR: https://phabric.freebsd.org/D498
Reviewed by: grehan, neel
MFC after: 1 week
framebuffer drivers. This lets ofwfb work with xf86-video-scfb and makes
the driver much more generic and less PCI-centric. This changes some
user-visible behavior and will require updates to the xorg-server port
on PowerPC when using ATI graphics cards.
some parts of the checks are in fact redundand in the surrounding
code, and it is more clear what the conditions are by direct testing
of the flags. Two of the three macros were only used in assertions.
In vnlru_free(), all relevant parts of vholdl() were already inlined,
except the increment of v_holdcnt itself. Do not call vholdl() to do
the increment as well, this allows to make assertions in
vholdl()/vhold() more strict.
In v_incr_usecount(), call vholdl() before incrementing other ref
counters. The change is no-op, but it makes less surprising to see
the vnode state in debugger if interrupted inside v_incr_usecount().
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Increase default ARC buf_hash_table size. When typical block size is small,
the hash table could be too small, which would lead to long hash chains and
limit performance for cached reads.
A new loader tunable, vfs.zfs.arc_average_blocksize, have been added which
allows users to override the default assumption of average (typical) block
size. Old default was 65536 (64 KiB) and new default is 8192 (8 KiB).
Illumos issue:
5034 ARC's buf_hash_table is too small
MFC after: 2 weeks
Change dn->dn_dbufs from linked list to AVL tree.
Illumos issues:
4873 zvol unmap calls can take a very long time for larger datasets
MFC after: 2 weeks
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Approved by: Gordon Ross <gwr@nexenta.com>
illumos/illumos-gate@63e911b6fc
code behave more like it is on Solaris.
Reported by: avg
Reviewed by: avg, mav (but bugs are mine)
Differential Revision: https://phabric.freebsd.org/D457
moved from the stack into the tag structure. In retrospect that was a bad
idea, because nothing protects that array from concurrent access by
multiple threads.
This change moves the array to the map structure (actually it's allocated
following the structure, but all in a single malloc() call).
This also establishes a "sane" limit of 4096 segments per map. This is
mostly to prevent trying to allocate all of memory if someone accidentally
uses a tag with nsegments set to BUS_SPACE_UNRESTRICTED. If there's ever
a genuine need for more than 4096, don't hesitate to increase this (or
maybe make it tunable).
Reviewed by: cognet
