write is a disk write request that tells the disk that the buffer
being written must be committed to the media along with any writes
that preceeded it before any future blocks may be written to the drive.
Barrier writes are provided by adding the functions bbarrierwrite
(bwrite with barrier) and babarrierwrite (bawrite with barrier).
Following a bbarrierwrite the client knows that the requested buffer
is on the media. It does not ensure that buffers written before that
buffer are on the media. It only ensure that buffers written before
that buffer will get to the media before any buffers written after
that buffer. A flush command must be sent to the disk to ensure that
all earlier written buffers are on the media.
Reviewed by: kib
Tested by: Peter Holm
blocking modes described in section 3.4.3 of RFC 2783, allowing the caller
to retrieve the most recent values without blocking, to block for a specified
time, or to block forever.
Reviewed by: discussion on hackers@
now disables read-ahead. It used to effectively restore the system default
readahead hueristic if it had been changed; a negative value now restores
the default.
Reviewed by: kib
every architecture's busdma_machdep.c. It is done by unifying the
bus_dmamap_load_buffer() routines so that they may be called from MI
code. The MD busdma is then given a chance to do any final processing
in the complete() callback.
The cam changes unify the bus_dmamap_load* handling in cam drivers.
The arm and mips implementations are updated to track virtual
addresses for sync(). Previously this was done in a type specific
way. Now it is done in a generic way by recording the list of
virtuals in the map.
Submitted by: jeff (sponsored by EMC/Isilon)
Reviewed by: kan (previous version), scottl,
mjacob (isp(4), no objections for target mode changes)
Discussed with: ian (arm changes)
Tested by: marius (sparc64), mips (jmallet), isci(4) on x86 (jharris),
amd64 (Fabian Keil <freebsd-listen@fabiankeil.de>)
Older entries should be 'before' newer entries in the new buffer too
and there should be no zero-filled gap between them.
Pointed out by: jhb
MFC after: 3 days
X-MFC with: r246282
until child performs exec(). The behaviour is reasonable when a
debugger is the real parent, because the parent is stopped until
exec(), and sending a debugging event to the debugger would deadlock
both parent and child.
On the other hand, when debugger is not the parent of the vforked
child, not sending debugging signals makes it impossible to debug
across vfork.
Fix the issue by declining generating debug signals only when vfork()
was done and child called ptrace(PT_TRACEME). Set a new process flag
P_PPTRACE from the attach code for PT_TRACEME, if P_PPWAIT flag is
set, which indicates that the process was created with vfork() and
still did not execed. Check P_PPTRACE from issignal(), instead of
refusing the trace outright for the P_PPWAIT case. The scope of
P_PPTRACE is exactly contained in the scope of P_PPWAIT.
Found and tested by: zont
Reviewed by: pluknet
MFC after: 2 weeks
Posix requires that open(2) is restartable for SA_RESTART.
For non-posix objects, in particular, devfs nodes, still disable
automatic restart of the opens. The open call to a driver could have
significant side effects for the hardware.
Noted and reviewed by: jilles
Discussed with: bde
MFC after: 2 weeks
cpuset mask for the associated interrupt thread.
The text used above is verbatim from r195249 and the code should now be
in line with the intent of that commit.
195702, 195703, and 195821 prevented a thread from suspending while holding
locks inside of NFS by forcing the thread to fail sleeps with EINTR or
ERESTART but defer the thread suspension to the user boundary. However,
this had the effect that stopping a process during an NFS request could
abort the request and trigger EINTR errors that were visible to userland
processes (previously the thread would have suspended and completed the
request once it was resumed).
This change instead effectively masks stop signals while in the NFS client.
It uses the existing TDF_SBDRY flag to effect this since SIGSTOP cannot
be masked directly. Also, instead of setting PBDRY on individual sleeps,
the NFS client now sets the TDF_SBDRY flag around each NFS request and
stop signals are masked for all sleeps during that region (the previous
change missed sleeps in lockmgr locks). The end result is that stop
signals sent to threads performing an NFS request are completely
ignored until after the NFS request has finished processing and the
thread prepares to return to userland. This restores the behavior of
stop signals being transparent to userland processes while still
preventing threads from suspending while holding NFS locks.
Reviewed by: kib
MFC after: 1 month
Only during very early boot, before malloc(9) is functional (SI_SUB_KMEM),
the static ktr_buf_init is used. Size of the static buffer is determined
by a new kernel option KTR_BOOT_ENTRIES. Its default value is 1024.
This commit builds on top of r243046.
Reviewed by: alc
MFC after: 17 days
And provide kernel compiler version as a sysctl as well.
This is useful while we have gcc and clang cohabitation.
This could be even more useful when we have support
for external toolchains.
In cooperation with: mjg
MFC after: 13 days
in kern_wait6(), which is called by kern_wait(). Remove the redundand
check, introduced in r243136, and add a comment noting this, to make
the code less confusing.
The blank lines are added to properly delineate the scope of the
preceeding comments.
Noted by: "Jukka A. Ukkonen" <jau@iki.fi>
MFC after: 1 week
tunable_mbinit() where it is next to where it is used later.
Change the sysinit level of tunable_mbinit() from SI_SUB_TUNABLES
to SI_SUB_KMEM after the VM is running. This allows to use better
methods to determine the effectively available physical and virtual
memory available to the kernel.
Update comments.
In a second step it can be merged into mbuf_init().
When maxusers was unrestricted and maxfiles was allowed to autotune
much higher the result was that ncallout which was based on maxfiles
and maxproc grew much higher than was needed.
To fix this clip autotuning to the same number we would get with
the old maxusers algorithm which would stop scaling at 384
maxusers.
Growing ncalout higher is not likely to be needed since most consumers
of timeout(9) are gone and any higher value for ncallout causes the
callwheel hashes to be much larger than will even be needed for
most applications.
MFC after: 1 month
Reviewed by: mav
Set the v_hash for a new vnode in the getnewvnode() to the value
calculated based on the vnode structure address. Filesystems using
vfs_hash_insert() override the v_hash using the standard formula of
(inode_number + mnt_hashseed). For other filesystems, the
initialization allows the vfs_hash_index() to provide useful hash too.
Suggested, reviewed and tested by: peter
Sponsored by: The FreeBSD Foundation
MFC after: 5 days
pre-masked hash for the given vnode. The function assumes that
vp->v_hash is initialized by the filesystem vnode instantiation
function. At the moment, it is only done if filesystem uses
vfs_hash_insert().
Reviewed by: peter
Tested by: peter, pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 5 days
