Since VFS does not/cannot stop writes, sync might run indefinitely, or
be a wrong thing to do at all. E. g. NFS ignores VFS_SYNC() for
forced unmounts, since non-responding server does not allow sync to
finish. On the other hand, filesystems can and do stop writes using
fs-specific facilities, and should already fully flush caches in
VFS_UNMOUNT() due to the race.
Adjust msdosfs tp sync in unmount for forced call, to accomodate the
new behaviour. Note that it is still racy, since writes are not
stopped.
Discussed with: avg, bjk, mckusick
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
to be called before suspension and after resume, correspondingly. The
syncer_suspend() ensures that all filesystems dirty data and metadata
are saved to the permanent storage, and stops kernel threads which
might modify filesystems. The syncer_resume() restores stopped
threads.
For now, only syncer is stopped. This is needed, because each sync
loop causes superblock updates for UFS.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
the vnode owning the buffer is not locked. More, it cannot be locked
safely, since getnewbuf_reuse_bp() is called from newbuf(), and some
other vnode is already locked, for which reused buffer will be
reassigned.
As the consequence, reclamation of the owning vnode could go in
parallel, in particular, the call to vnode_destroy_vobject(), which
deallocates the vm object and zeroes the v_bufobj->bo_object. Note
that the pages wired by the buffer are left wired and can be safely
freed by the vfs_vmio_release() without the need for the vm object
lock. Also, seeing stale pointer to the v_object is safe due to vm
object type stability.
Check for bo_bufobj != NULL and cache the value in local variable to
avoid trying to lock NULL vm object.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
preparation for the global stop commit.
Move the code to weed suspended or sleeping threads into the
appropriate state, into the helper weed_inhib(). Current code already
has deep nesting and hard to follow [1].
Add currently useless helper remain_for_mode(), which returns the
count of threads which are allowed to run, according to the
single-threading mode.
In thread_single_end(), do not save curthread into local variable, it
is unused after, except to find curproc.
Remove stray empty line.
Requested by: avg [1]
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
for the suspension.
Currently, the loop performs uninterruptible cv_wait(9) call, which
prevents suspension until child allows further execution of parent.
If child is stopped, suspension or single-threading is delayed
indefinitely.
Create a helper thread_suspend_check_needed() to identify the need for
a call to thread_suspend_check(). It is required since call to the
thread_suspend_check() cannot be safely done while owning the child
(p2) process lock. Only when suspension is needed, drop p2 lock and
call thread_suspend_check(). Perform wait for cv with timeout, in
case suspend is requested after wait started; I do not see a better
way to interrupt the wait.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
multithreaded status of the process.
The stopped state must be cleared before P_WEXIT is set. A stop
signal delivered just before first PROC_LOCK() block in exit1(9) would
put the process into pending stop with P_WEXIT set or assertion
triggered. Also recheck for the suspension after failed
thread_single(9) call, since process lock could be dropped.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
In the old days callout(9) had 1 tick precision and that was inadequate
for some uses, e.g. DTrace profile module, so we had to emulate cyclic
API and behavior. Now we can directly use callout(9) in the very few
places where cyclic was used.
Differential Revision: https://reviews.freebsd.org/D1161
Reviewed by: gnn, jhb, markj
MFC after: 2 weeks
Provide pru_ready for AF_LOCAL sockets. Local sockets sendsdata directly
to the receive buffer of the peer, thus pru_ready also works on the peer
socket.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
sending not ready data:
o Add new flag to pru_send() flags - PRUS_NOTREADY.
o Add new protocol method pru_ready().
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
o Introduce a notion of "not ready" mbufs in socket buffers. These
mbufs are now being populated by some I/O in background and are
referenced outside. This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
freed.
o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
The sb_ccc stands for ""claimed character count", or "committed
character count". And the sb_acc is "available character count".
Consumers of socket buffer API shouldn't already access them directly,
but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
search.
o New function sbready() is provided to activate certain amount of mbufs
in a socket buffer.
A special note on SCTP:
SCTP has its own sockbufs. Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs. Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them. The new
notion of "not ready" data isn't supported by SCTP. Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does. This was discussed with rrs@.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
crowded as we now are at about 70k. Bump the limit to 1MB instead
which is still quite a reasonable limit and allows for future growth
of this file and possible future expansion to additional data.
MFC After: 2 weeks
recursion on mutex initialization.
The only places where the recursive acquire is performed are read and
write filters, since knlist, which uses the pipe pair mutex as lock,
is locked when filter is called.
The recursion was added in r93296, and consistent locking for
kn_fop->f_event() introduced in r133741.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
This allows one to make a kernel module to tune the
number of queues before the driver loads.
This is needed so that a module at SI_SUB_CPU can set
tunables for these drivers to take. Otherwise getenv
is called too early by the TUNABLE macros.
Reviewed by: smh
Phabric: https://reviews.freebsd.org/D1149
- Threads lifetime cycle, in particular, counting of the threads in
the process, and interlocking with process mutex and thread lock.
The main reason of this is that turnstile locks are after thread
locks, so you e.g. cannot unlock blockable mutex (think process
mutex) while owning thread lock.
- Virtual and profiling itimers, since the timers activation is done
from the clock interrupt context. Replace the p_slock by p_itimmtx
and PROC_ITIMLOCK().
- Profiling code (profil(2)), for similar reason. Replace the p_slock
by p_profmtx and PROC_PROFLOCK().
- Resource usage accounting. Need for the spinlock there is subtle,
my understanding is that spinlock blocks context switching for the
current thread, which prevents td_runtime and similar fields from
changing (updates are done at the mi_switch()). Replace the p_slock
by p_statmtx and PROC_STATLOCK().
The split is done mostly for code clarity, and should not affect
scalability.
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
method needs pre-reset state of the ps_siginfo to correctly construct
signal frame.
Move sigdflt() call after the sv_sendsig() invocation in postsig().
Simultaneously extract common code from trapsignal() and postsig()
into new helper postsig_done().
Submitted by: rea
MFC after: 1 week
a new per-device '%domain' sysctl node that returns the NUMA domain a
device is associated with if it is associated with one.
Note that this API is still a WIP and might change before 11.0 actually
ships.
Differential Revision: https://reviews.freebsd.org/D930
Reviewed by: kib, adrian
o Provide a new VOP_GETPAGES_ASYNC(), which works like VOP_GETPAGES(), but
doesn't sleep. It returns immediately, and will execute the I/O done handler
function that must be supplied as argument.
o Provide VOP_GETPAGES_ASYNC() for the FFS, which uses vnode_pager.
o Extend pagertab to support pgo_getpages_async method, and implement this
method for vnode_pager.
Reviewed by: kib
Tested by: pho
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
- Dump an NT_X86_XSTATE note if XSAVE is in use. This note is designed
to match what Linux does in that 1) it dumps the entire XSAVE area
including the fxsave state, and 2) it stashes a copy of the current
xsave mask in the unused padding between the fxsave state and the
xstate header at the same location used by Linux.
- Teach readelf() to recognize NT_X86_XSTATE notes.
- Change PT_GET/SETXSTATE to take the entire XSAVE state instead of
only the extra portion. This avoids having to always make two
ptrace() calls to get or set the full XSAVE state.
- Add a PT_GET_XSTATE_INFO which returns the length of the current
XSTATE save area (so the size of the buffer needed for PT_GETXSTATE)
and the current XSAVE mask (%xcr0).
Differential Revision: https://reviews.freebsd.org/D1193
Reviewed by: kib
MFC after: 2 weeks
Early UART should be released right after system console initialization is
completed. Otherwise, after cninit() both early and system console coexist
what may lead to various issues (i.a. writing to unmapped early
UART address). This cannot be done in cninit_finish() since it can be
called late at the end of MI configuration.
Obtained from: Semihalf
Reviewed by: andrew
Sponsored by: The FreeBSD Foundation
This significantly reduces lock contention when adding/removing knotes
on busy multi-kq system... Next step is to cache these references per
kq.. i.e. kq refs it once and keeps a local ref count so that the same
refs don't get accessed by many cpus...
only allocate a knote when we might use it...
Add a new flag, _FORCEONESHOT.. This allows a thread to force the
delivery of another event in a safe manner, say waking up an idle http
connection to force it to be reaped...
If we are _DISABLE'ing a knote, don't bother to call f_event on it, it's
disabled, so won't be delivered anyways..
Tested by: adrian
Not all consumers providing fdp to copy from want files.
Perhaps these functions should be reorganized to better express the outcome.
This fixes up panics after r273895 .
Reported by: markj
uc_busy value, and not its address [1].
Remove the single use of the macro, write KASSERT() explicitely in the
code of umtxq_sleep_pi().
Submitted by: Eric van Gyzen <eric@vangyzen.net> [1]
MFC after: 1 week
have both kern_open() and kern_openat(); change the callers to use
kern_openat().
This removes one (sometimes two) levels of indirection and
consolidates arguments checks.
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
underlying file does not have DFLAG_SEEKABLE set [1].
For posix_fallocate(2), simplify error handling logic. Do return when
fp is not yet referenced.
Noted by: bde [1]
Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
sb_cc member of struct sockbuf to a couple of inline functions:
sbavail() and sbused()
Right now they are equal, but once notion of "not ready socket buffer data",
will be checked in, they are going to be different.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
