When safety requirements are met, it allows to avoid passing I/O requests
to GEOM g_up/g_down thread, executing them directly in the caller context.
That allows to avoid CPU bottlenecks in g_up/g_down threads, plus avoid
several context switches per I/O.
The defined now safety requirements are:
- caller should not hold any locks and should be reenterable;
- callee should not depend on GEOM dual-threaded concurency semantics;
- on the way down, if request is unmapped while callee doesn't support it,
the context should be sleepable;
- kernel thread stack usage should be below 50%.
To keep compatibility with GEOM classes not meeting above requirements
new provider and consumer flags added:
- G_CF_DIRECT_SEND -- consumer code meets caller requirements (request);
- G_CF_DIRECT_RECEIVE -- consumer code meets callee requirements (done);
- G_PF_DIRECT_SEND -- provider code meets caller requirements (done);
- G_PF_DIRECT_RECEIVE -- provider code meets callee requirements (request).
Capable GEOM class can set them, allowing direct dispatch in cases where
it is safe. If any of requirements are not met, request is queued to
g_up or g_down thread same as before.
Such GEOM classes were reviewed and updated to support direct dispatch:
CONCAT, DEV, DISK, GATE, MD, MIRROR, MULTIPATH, NOP, PART, RAID, STRIPE,
VFS, ZERO, ZFS::VDEV, ZFS::ZVOL, all classes based on g_slice KPI (LABEL,
MAP, FLASHMAP, etc).
To declare direct completion capability disk(9) KPI got new flag equivalent
to G_PF_DIRECT_SEND -- DISKFLAG_DIRECT_COMPLETION. da(4) and ada(4) disk
drivers got it set now thanks to earlier CAM locking work.
This change more then twice increases peak block storage performance on
systems with manu CPUs, together with earlier CAM locking changes reaching
more then 1 million IOPS (512 byte raw reads from 16 SATA SSDs on 4 HBAs to
256 user-level threads).
Sponsored by: iXsystems, Inc.
MFC after: 2 months
This shuld have been a problem since r230587. Not exactly sure why it
was not detected the last weeks with the tinderbox. I would assume
r255744 is what started to cause it.
MFC after: 1 week
of string format in a call so syslog
/usr/src/gnu/lib/libssp/../../../contrib/gcclibs/libssp/ssp.c:137:23:
warning: format string is not a string literal (potentially insecure)
[-Wformat-security]
syslog (LOG_CRIT, msg1);
^~~~
Reviewed by: dim@
the cfi(4) driver. It remained in the tree longer than would be ideal
due to the time required to bring cfi(4) to feature parity.
Sponsored by: DARPA/AFRL
MFC after: 3 days
Implement support for interrupt-parent nodes in simplebus. The current
implementation requires that device declarations have an interrupt-parent
node and that it point to a device that has registered itself as a
interrupt controller in fdt_ic_list_head and implements the fdt_ic
interface.
Sponsored by: DARPA/AFRL
64-bit debug data is only necessary for objects with greater than 4GB of
debug data, and is not used on other 64-bit FreeBSD targets.
Sponsored by: DARPA, AFRL
user. Kqueue now saves the ucred of the allocating thread, to
correctly decrement the counter on close.
Under some specific and not real-world use scenario for kqueue, it is
possible for the kqueues to consume memory proportional to the square
of the number of the filedescriptors available to the process. Limit
allows administrator to prevent the abuse.
This is kernel-mode side of the change, with the user-mode enabling
commit following.
Reported and tested by: pho
Discussed with: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
user. Kqueue now saves the ucred of the allocating thread, to
correctly decrement the counter on close.
Under some specific and not real-world use scenario for kqueue, it is
possible for the kqueues to consume memory proportional to the square
of the number of the filedescriptors available to the process. Limit
allows administrator to prevent the abuse.
This is kernel-mode side of the change, with the user-mode enabling
commit following.
Reported and tested by: pho
Discussed with: jmg
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
already. Also, according to the specs, GDRST register is not in the
power well, so the forcewake for reset status read is excessive for
this reason.
Use plain register read for waiting of the reset completion
notification, to avoid gt_lock recursion. Linux upstream did the
similar change, but their code was already restructured.
Reported by: ray
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
reduce lock congestion and improve SMP scalability of the SCSI/ATA stack,
preparing the ground for the coming next GEOM direct dispatch support.
Replace big per-SIM locks with bunch of smaller ones:
- per-LUN locks to protect device and peripheral drivers state;
- per-target locks to protect list of LUNs on target;
- per-bus locks to protect reference counting;
- per-send queue locks to protect queue of CCBs to be sent;
- per-done queue locks to protect queue of completed CCBs;
- remaining per-SIM locks now protect only HBA driver internals.
While holding LUN lock it is allowed (while not recommended for performance
reasons) to take SIM lock. The opposite acquisition order is forbidden.
All the other locks are leaf locks, that can be taken anywhere, but should
not be cascaded. Many functions, such as: xpt_action(), xpt_done(),
xpt_async(), xpt_create_path(), etc. are no longer require (but allow) SIM
lock to be held.
To keep compatibility and solve cases where SIM lock can't be dropped, all
xpt_async() calls in addition to xpt_done() calls are queued to completion
threads for async processing in clean environment without SIM lock held.
Instead of single CAM SWI thread, used for commands completion processing
before, use multiple (depending on number of CPUs) threads. Load balanced
between them using "hash" of the device B:T:L address.
HBA drivers that can drop SIM lock during completion processing and have
sufficient number of completion threads to efficiently scale to multiple
CPUs can use new function xpt_done_direct() to avoid extra context switch.
Make ahci(4) driver to use this mechanism depending on hardware setup.
Sponsored by: iXsystems, Inc.
MFC after: 2 months
files created by WITH_DEBUG_FILES. Also cleanup .symbols files from
the period between r244236 when .symbols were supported and r251512
when they were renamed to .debug.
Only propose to delete a .debug file if the corresponding library
itself was deleted already.
Reported by: des
Reviewed by: emaste (earlier version)
Approved by: bapt
MFC after: 3 days
_citrus_mapper_close again and result in a deadlock otherwise.
This is similar to NetBSD PR/24023 (fixed in their r1.5 of this file).
PR: bin/182994
Submitted by: Fabian Keil <fk fabiankeil de>
MFC after: 3 days
Restore BIO_UNMAPPED and BIO_TRANSIENT_MAPPING in biodonne() when unmapping
temporary mapped buffer. That fixes double unmap if biodone() called twice
for the same BIO (but with different done methods).
Move mapping removal before calling bio_done() method. I believe that it is
very wrong to do anything to BIO after reporting completion. kib@ thinks
it was done for some forgotten now case when bio_done() method needed mapped
buffer. But 1) if BIO was sent as unmapped, then IMO done() should be called
in the same way; 2) IMO there is no guatantee that buffer will be mapped at
this point at all, for example, if all underlying stack supports unmapped
I/O, so bio_done() handler can not expect that.
with CARP.
Currently, we've got a problem that interface isn't IFF_UP at the time
we assign it a redundant address, and the latter gets stuck in INIT state.
Additional SIOCSIFFLAGS from ifconfig(8) kicks it to a working state.
A proper fix is kernel side and appeared to be non-trivial, not to be
checked in before 10.0-RELEASE.
Submitted by: Ole Myhre <ole.myhre dataoppdrag.no>
the register based on the argument index rather than relying on the fields
in struct reg to be in the right order. This assumption is incorrect on
FreeBSD and generally led to bogus argument values for the sixth argument
of PID and USDT probes; the first five are passed directly to dtrace_probe()
via the fasttrap trap handler and so were correctly handled.
MFC after: 2 weeks
single kernel-wide soft update lock can be replaced with a
per-filesystem soft-updates lock. This per-filesystem lock will
allow each filesystem to have its own soft-updates flushing thread
rather than being limited to a single soft-updates flushing thread
for the entire kernel.
Move soft update variables out of the ufsmount structure and into
their own mount_softdeps structure referenced by ufsmount field
um_softdep. Eventually the per-filesystem lock will be in this
structure. For now there is simply a pointer to the kernel-wide
soft updates lock.
Change all instances of ACQUIRE_LOCK and FREE_LOCK to pass the lock
pointer in the mount_softdeps structure instead of a pointer to the
kernel-wide soft-updates lock.
Replace the five hash tables used by soft updates with per-filesystem
copies of these tables allocated in the mount_softdeps structure.
Several functions that flush dependencies when too many are allocated
in the kernel used to operate across all filesystems. They are now
parameterized to flush dependencies from a specified filesystem.
For now, we stick with the round-robin flushing strategy when the
kernel as a whole has too many dependencies allocated.
While there are many lines of changes, there should be no functional
change in the operation of soft updates.
Tested by: Peter Holm and Scott Long
Sponsored by: Netflix
from the kernel build until it is ready.
sys/conf/files:
Remove the entry for xen/evtchn/evtchn_dev.c so it is not included
in any kernel builds.
Noticed by: smh
Add KASSERTS that soft dependency functions only get called
for filesystems running with soft dependencies. Calling these
functions when soft updates are not compiled into the system
become panic's.
No functional change.
Tested by: Peter Holm and Scott Long
Sponsored by: Netflix
Ensure that softdep_unmount() and softdep_setup_sbupdate()
only get called for filesystems running with soft dependencies.
No functional change.
Tested by: Peter Holm and Scott Long
Sponsored by: Netflix
Freescale SoCs including the i.MX series. This also works for the newer
SoCs with the ENET gigabit controller, but doesn't use any of the new
hardware features other than enabling gigabit speed.
