Combined with earlier nstart/nend removal it allows to remove several locks
from request path of GEOM and few other places. It would be cool if we had
more SMP-friendly statistics, but this helps too.
Sponsored by: iXsystems, Inc.
In IRC, sfs_ finally managed to get a good trace of a kernel panic that was
happening when attempting to use webengine.
As it turns out, we were using vtophys() from interrupt context on an idle
thread in opal_hmi_handler2().
Since this involves locking the kernel pmap on PPC64 at the moment, this
ended up tripping a KASSERT in mtx_lock(), which then caused a parallel
panic stampede.
So, avoid this by preallocating the flags variable and storing it in PCPU.
Fixes "panic: mtx_lock() by idle thread 0x... on sleep mutex kernelpmap".
Differential Revision: https://reviews.freebsd.org/D22962
Allow loadable modules that provide random entropy source(s) to safely
unload. Prior to this change, no driver could ensure that their
random_source structure was not being used by random_harvestq.c for any
period of time after invoking random_source_deregister().
This change converts the source_list LIST to a ConcurrencyKit CK_LIST and
uses an epoch(9) to protect typical read accesses of the list. The existing
HARVEST_LOCK spin mutex is used to safely add and remove list entries.
random_source_deregister() uses epoch_wait() to ensure no concurrent
source_list readers are accessing a random_source before freeing the list
item and returning to the caller.
Callers can safely unload immediately after random_source_deregister()
returns.
Reviewed by: markj
Approved by: csprng(markm)
Discussed with: jhb
Differential Revision: https://reviews.freebsd.org/D22489
Those counters were abused for decade to workaround broken orphanization
process in different classes by delaying the call while there are active
requests. But from one side it did not close all the races, while from
another was quite expensive on SMP due to trashing twice per request cache
lines of consumer and provider and requiring locks. It lost its sense
after I manually went through all the GEOM classes in base and made
orphanization wait for either provider close or request completion.
Consumer counters are still used under INVARIANTS to detect premature
consumer close and detach. Provider counters are removed completely.
Sponsored by: iXsystems, Inc.
arm64 is still lacking a fasttrap implementation, which is required to
actually enable userland probes, but this at least allows USDT probes to
be linked into userland applications.
Submitted by: Klaus Küchemann <maciphone2@googlemail.com> (original)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22360
This code was not actively maintained since it was introduced 10 years ago.
It lacks support for many later GEOM features, such as direct dispatch,
unmapped I/O, stripesize/stripeoffset, resize, etc. Plus it is the only
remaining use of GEOM nstart/nend request counters, used there to implement
live insertion/removal, questionable by itself. Plus, as number of people
commented, GEOM is not the best place for I/O scheduler, since it has
limited information about layers both above and below it, required for
efficient scheduling. Plus with the modern shift to SSDs there is just no
more significant need for this kind of scheduling.
Approved by: imp, phk, luigi
Relnotes: yes
We now set PGA_DEQUEUE on a managed page when it is wired after
allocation, and vm_page_mvqueue() ignores pages with this flag set,
ensuring that they do not end up in the page queues. However, this is
not sufficient for managed fictitious pages or pages managed by the
TTM. In particular, the TTM makes use of the plinks.q queue linkage
fields for its own purposes.
PR: 242961
Reported and tested by: Greg V <greg@unrelenting.technology>
If we postpone consumer destruction till close, then the close calls should
not be ignored. Delay geom withering till the last close too.
MFC after: 2 weeks
X-MFC-with: r356162
Sponsored by: iXsystems, Inc.
Previous code closed and destroyed consumer even with I/O in progress.
This patch postpones the destruction till the last close.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
symbols from the linked kernel.
The main thrust of this change is to generate a kernel that has the arm
"marker" symbols stripped. Marker symbols start with $a, $d, $t or $x, and
are emitted by the compiler to tell other toolchain components about the
locations of data embedded in the instruction stream (literal-pool
stuff). They are used for generating mixed-endian binaries (which we don't
support). The linked kernel has approximately 21,000 such symbols in it,
wasting space (500K in kernel.full, 190K in the final linked kernel), and
sometimes obscuring function names in stack tracebacks.
This change also simplifies the way the kernel is linked. Instead of using
sed to generate two different ldscript files to generate both an elf kernel
and a binary (elf headers stripped) kernel, we now use a single ldscript
that refers to a "text_start" symbol, and we provide the value for that
symbol using --defsym on the linker command line.
Remove temporary compatibility layer introduced in r351729. More that 3 months
should be enough for everybody who runs HEAD to upgrade to the new kernel
already.
Reviewed by: imp, mjg (mentor)
Approved by: mjg (mentor)
Differential Revision: https://reviews.freebsd.org/D22958
Previous code closed and detached consumer even with I/O still in progress.
This patch adds locking and request counting to postpone the close till
the last of running requests completes.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
Change the "count_until_fail" option of gnop, now it enables the failing
rating instead of setting them to 100%.
The original patch introduced the new flag, which sets the fail/rate to 100%
after N requests. In some cases, we don't want to have 100% of failure
probabilities. We want to start failing at some point.
For example, on the early stage, we may like to allow some read/writes requests
before having some requests delayed - when we try to mount the partition,
or when we are trying to import the pool.
Another case may be to check how scrub in ZFS will behave on different stages.
This allows us to cover more cases.
The previous behavior still may be configured.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22632
Thanks to this option we can create more then one gnop provider from
single provider. This may be useful for temporary labeling some data
on the disk.
Reviewed by: markj, allanjude, bcr
Differential Revision: https://reviews.freebsd.org/D22304
This fixes a regression in r356155, introduced at the last minute. In
particular, we must clear PGA_REQUEUE_HEAD before inserting into any
queue besides PQ_INACTIVE since that operation is implemented only for
PQ_INACTIVE.
Reported by: pho, Jenkins via lwhsu
devices. It's required for LTP, among other things. It's not
complete, but good enough for now.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D22950
With WITNESS enabled we see the following warning:
lock order reversal: (sleepable after non-sleepable)
1st 0xffffffd0847c7210 fu540spi0 (fu540spi0) @
/usr/home/kp/axiado/hornet-freebsd/src/sys/riscv/sifive/fu540_spi.c:297
2nd 0xffffffc00372bb30 Clock topology lock (Clock topology lock) @
/usr/home/kp/axiado/hornet-freebsd/src/sys/dev/extres/clk/clk.c:1137
stack backtrace:
#0 0xffffffc0002a579e at witness_checkorder+0xb72
#1 0xffffffc0002a5556 at witness_checkorder+0x92a
#2 0xffffffc000254c7a at _sx_slock_int+0x66
#3 0xffffffc00025537a at _sx_slock+0x8
#4 0xffffffc000123022 at clk_get_freq+0x38
#5 0xffffffc0005463e4 at __clzdi2+0x2bb8
#6 0xffffffc00014af58 at randomdev_getkey+0x76e
#7 0xffffffc0001278b0 at simplebus_add_device+0x7ee
#8 0xffffffc00027c9a8 at device_attach+0x2e6
#9 0xffffffc00027c634 at device_probe_and_attach+0x7a
#10 0xffffffc00027d76a at bus_generic_attach+0x10
#11 0xffffffc00014aab0 at randomdev_getkey+0x2c6
#12 0xffffffc00027c9a8 at device_attach+0x2e6
#13 0xffffffc00027c634 at device_probe_and_attach+0x7a
#14 0xffffffc00027d76a at bus_generic_attach+0x10
#15 0xffffffc000278bd2 at config_intrhook_oneshot+0x52
#16 0xffffffc000278b3e at config_intrhook_establish+0x146
#17 0xffffffc000278cf2 at config_intrhook_disestablish+0xfe
The clock topology lock can sleep, which means we cannot attempt to
acquire it while holding the non-sleepable mutex.
Fix that by retrieving the clock speed once, during attach and not every
time during SPI transaction setup.
Submitted by: kp
Sponsored by: Axiado
This should help people examining src.conf(5) draw the connection between
the HTTPD knobs and the particular implementation we're installing,
simple_httpd.
Reported by: saken658 via GitHub
Previous code closed and destroyed consumer even with I/O in progress.
This patch postpones the destruction till the last close, identical to
GEOM_STRIPE, since they seem to have common origin.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
The previous series of patches orphaned some vm_page functions, so
remove them.
Reviewed by: dougm, kib
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22886
With the previous reviews, the page lock is no longer required in order
to perform queue operations on a page. It is also no longer needed in
the page queue scans. This change effectively eliminates remaining uses
of the page lock and also the false sharing caused by multiple pages
sharing a page lock.
Reviewed by: jeff
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22885
Some recent work aims to remove the use of the page lock for
synchronizing updates to page queue state. This change adds a mechanism
to preserve the existing behaviour of lazily dequeuing wired pages,
which was previously synchronized using the page lock.
Handle this by setting PGA_DEQUEUE when a managed page's wire count
transitions from 0 to 1. When the page daemon encounters a page with a
flag in PGA_QUEUE_OP_MASK set, it creates a batch queue entry for that
page, but in so doing it does not modify the page itself and thus racing
with a concurrent free of the page is harmless. The flag is advisory;
the page daemon still checks for wirings after acquiring the object and
page xbusy locks.
vm_page_unwire_managed() now clears PGA_DEQUEUE on a 1->0 transition.
It must do this before dropping the reference to avoid a use-after-free
but also handles races with concurrent wirings to ensure that
PGA_DEQUEUE is not left unset on a wired page.
Reviewed by: jeff
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22882
This is in preparation for eliminating the use of the vm_page lock for
protecting queue state operations.
Introduce the vm_page_pqstate_commit_*() functions. These functions act
as helpers around vm_page_astate_fcmpset() and are specialized for
specific types of operations. vm_page_pqstate_commit() wraps these
functions.
Convert a number of routines to use these new helpers. Use
vm_page_release_toq() in vm_page_unwire() and vm_page_release() to
atomically release a wiring reference and release the page into a queue.
This has the side effect that vm_page_unwire() will leave the page in
the active queue if it is already present there.
Convert the page queue scans to use the new helpers. Simplify
vm_pageout_reinsert_inactive(), which requeues pages that were found to
be busy during an inactive queue scan, to avoid duplicating the work of
vm_pqbatch_process_page(). In particular, if PGA_REQUEUE or
PGA_REQUEUE_HEAD is set, let that be handled during batch processing.
Reviewed by: jeff
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22770
Differential Revision: https://reviews.freebsd.org/D22771
Differential Revision: https://reviews.freebsd.org/D22772
Differential Revision: https://reviews.freebsd.org/D22773
Differential Revision: https://reviews.freebsd.org/D22776
This avoids duplicating the work of the page daemon's active queue scan.
Moreover, this duplication was inconsistent:
- PGA_REFERENCED is not counted in act_count unless pmap_ts_referenced()
returned 0, but the page daemon always counts PGA_REFERENCED towards
the activation count.
- The swapout daemon always activates a referenced page, but the page
daemon only does so when the containing object is mapped at least
once.
The main purpose of swapout_deactivate_pages() is to shrink the number
of pages mapped into a given pmap. To do this without unmapping active
pages, use the non-destructive pmap_is_referenced() instead of the
destructive pmap_ts_referenced() and deactivate pages accordingly.
This simplifies some future changes to the locking protocol for page
queue state.
Reviewed by: kib
Discussed with: jeff
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22674
Previous code closed and destroyed direct read consumer even with I/O still
in progress. This patch adds locking and request counting to postpone the
close till the last of running requests completes.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
In r355270 by me, vm_object_shadow() was changed to handle the
reference counting for the shared case, but the extra reference that
was done in vmspace_fork() for the shared/need_copy case was not
removed.
Submitted by: jeff
This driver configure the registers in the GRF according to the value
of the regulators for the platform.
Some IP can run with either 3.0V or 1.8V, if we don't configure them
correctly according to the external voltage used they will not work.
It's only done at boot time for now and might be needed at runtime for
IP like sdmmc.
Reviewed by: mmel
Tested On: RockPro64, Firefly-RK3399 (gonzo), AIO-3288 (mmel)
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22854
The RK808 driver was missing the LDO and switch regulators.
Add support for them.
Reviewed by: mmel
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D22852
Previous code destroyed softc even with provider still open, that resulted
in panic under load. This change postpones the free till the final close,
when we know for sure there will be no more I/O requests.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
