Summary:
CloudABI provides two different types of futex objects: read-write locks
and condition variables. There is no need to provide separate support
for once objects and thread joining, as these are efficiently simulated
by blocking on a read-write lock. Mutexes simply use read-write locks.
Condition variables always have a lock object associated to them. They
always know to which lock a thread needs to be migrated if woken up.
This allows us to implement requeueing. A broadcast on a condition
variable will never cause multiple threads to be woken up at once. They
will be woken up iteratively.
This implementation still has lots of room for improvement. Locking is
coarse and right now we use linked lists to store all of the locks and
condition variables, instead of using a hash table. The primary goal of
this implementation was to behave correctly. Performance will be
improved as we go.
Test Plan:
This futex implementation has been in use for the last couple of months
and seems to work pretty well. All of the cloudlibc and libc++ unit
tests seem to pass.
Reviewers: dchagin, kib, vangyzen
Subscribers: imp
Differential Revision: https://reviews.freebsd.org/D3148
Futex object scopes have been renamed from using their own constants to
simply reusing the existing CLOUDABI_MAP_{PRIVATE,SHARED} flags, as they
are more accurate in this context.
identification (e.g. isa:0x3f0 or pci0:2:1:0). In libbus,
the device is turned into a path name. For bus_space_map(),
the resource is now specified in a second argument.
Before:
bus.map('/dev/proto/pci0:2:1:0/pcicfg')
busdma.tag_create('/dev/proto/pci0:2:1:0/busdma', ...)
Now:
bus.map('pci0:2:1:0', 'pcicfg')
busdma.tag_create('pci0:2:1:0', ...)
Rationale: ident(1) is useful out of RCS, lot of scripts are using ident(1) and
failing when base is built WITHOUT_RCS.
This version is:
- fully compatible with RCS 5.7 ident.
- fully compatible with RCS 5.9 ident.
- passes all ident test from GNU RCS 5.9 test suite
This version has support for: svn extension for the Keyword id (double colon and
# before last $)
Différences with GNU RCS ident:
- no long options as found in GNU RCS 5.9 (but not commented there).
- '-V' reports nothing but has been added for compatibility.
Differential Revision: https://reviews.freebsd.org/D3200
Reviewed by: pfg
Currently LOCK_DEBUG is always defined in sys/lock.h (0 or 1).
This means that debugging code always built. In addition the kernel
modules have always defined LOCK_DEBUG as 1. So, debugging rmlock code
is always used by kernel modules.
MFC after: 1 week
determining whether a node changed.
Other filesystems, e.g., UFS, only check on seconds, when determining
whether something changed.
This also corrects the birthtime case, where we checked tv_nsec
twice, instead of tv_sec and tv_nsec (PR).
PR: 201284
Submitted by: David Binderman
Patch suggested by: kib
Reviewed by: kib
MFC after: 2 weeks
Committed from: Essen FreeBSD Hackathon
This is required by our FORTIFY_SOURCE implementation as it
does more inlining. As a rule of thumb, FORTIFY_SOURCE doubles
the number of inlines except that in grep inlining
blows up for some reason.
Assume that a vnode is mapped shared and mlocked(), and then the vnode
is truncated, or truncated and then again extended past the mapping
point EOF. Truncation removes the pages past the truncation point,
and if pages are later created at this range, they are not properly
mapped into the mlocked region, and their wiring count is wrong.
The revert leaves the invalidated but wired pages on the object queue,
which means that the pages are found by vm_object_unwire() when the
mapped range is munlock()ed, and reused by the buffer cache when the
vnode is extended again.
The changes in r173708 were required since then vm_map_unwire() looked
at the page tables to find the page to unwire. This is no longer
needed with the vm_object_unwire() introduction, which follows the
objects shadow chain.
Also eliminate OBJPR_NOTWIRED flag for vm_object_page_remove(), which
is now redundand, we do not remove wired pages.
Reported by: trasz, Dmitry Sivachenko <trtrmitya@gmail.com>
Suggested and reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
to no longer claim they are experimental.
Reviewed by: rwatson@, wblock@
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D2985
b_kvabase when the buffer is reclaimed. Otherwise, if b_data for the
mapped buffer was adjusted with the page-offset portion of b_offset,
nothing would re-adjust the b_data, which breaks buffer management
code which expects page-aligned b_data (see e.g. bpman_qenter(), which
skips partial pages).
Fix a minor issue with the GB_KVAALLOC requests, which could result in
returning the mapped buffer if the reused buffer is mapped and have
the right amount of KVA reserved.
Improve assertion in the vfs_buf_check_mapped() to catch unmapped
buffers which have their b_data incorrectly adjusted with offset.
Reported and tested by: pho (previous version)
Reviewed by: jeff (previous version)
Sponsored by: The FreeBSD Foundation
but it's hard to find and easy to miss.
Reviewed by: wblock@
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3183
Correctly escape literal % for display
This fixes segfaults in 32bit arches caused by r285734
Reviewed by: ngie
Approved by: dim
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D3191
This is required in order for us to support deterministic mode by
default. If multiple -D or -U options are specified on the command
line, the final one takes precedence. GNU ar also uses -U for this.
An equivalent change will be applied to ELF Tool Chain's version of ar.
PR: 196929
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3175
uart_bus_attach() during its test that 20 iterations weren't sufficient
for clearing all pending interrupts, assuming this means that hardware
is broken and doesn't deassert interrupts. However, under pressure, 20
iterations also can be insufficient for clearing all pending interrupts,
leading to a panic as intr_event_handle() tries to schedule an interrupt
handler not registered. Solve this by introducing a flag that is set in
test mode and otherwise restores pre-r253161 behavior of uart_intr(). The
approach of additionally registering uart_intr() as handler as suggested
in PR 194979 is not taken as that in turn would abuse special pccard and
pccbb handling code of intr_event_handle(). [1]
- Const'ify uart_driver_name.
- Fix some minor style bugs.
PR: 194979 [1]
Reviewed by: marcel (earlier version)
MFC after: 3 days
raw data to the doorbell offset in order to clarify the intent and for
avoiding unnecessarily converting the endianess back and forth.
Unfortunately, the same can't be done in mpt_recv_handshake_reply() as
16-bit data needs to be read using 32-bit bus accessors.
- In mpt_recv_handshake_reply(), get rid of a redundant variable.
MFC after: 1 fortnight
