The main purpose of this patch is to fix handling of unpause calls
from PM while another call is ongoing. The solution to this problem
sparked a full revision of the threading model, consisting of a large
number of related changes:
- all active worker threads are now always associated with a process,
and every process has at most one active thread working for it;
- the process lock is always held by a process's worker thread;
- a process can now have both normal work and postponed PM work
associated to it;
- timer expiry and non-postponed PM work is done from the main thread;
- filp garbage collection is done from a thread associated with VFS;
- reboot calls from PM are now done from a thread associated with PM;
- the DS events handler is protected from starting multiple threads;
- support for a system worker thread has been removed;
- the deadlock recovery thread has been replaced by a parameter to the
worker_start() function; the number of worker threads has
consequently been increased by one;
- saving and restoring of global but per-thread variables is now
centralized in worker_suspend() and worker_resume(); err_code is now
saved and restored in all cases;
- the concept of jobs has been removed, and job_m_in now points to a
message stored in the worker thread structure instead;
- the PM lock has been removed;
- the separate exec lock has been replaced by a lock on the VM
process, which was already being locked for exec calls anyway;
- PM_UNPAUSE is now processed as a postponed PM request, from a thread
associated with the target process;
- the FP_DROP_WORK flag has been removed, since it is no longer more
than just an optimization and only applied to processes operating on
a pipe when getting killed;
- assignment to "fp" now takes place only when obtaining new work in
the main thread or a worker thread, when resuming execution of a
thread, and in the special case of exiting processes during reboot;
- there are no longer special cases where the yield() call is used to
force a thread to run.
Change-Id: I7a97b9b95c2450454a9b5318dfa0e6150d4e6858
The T_DUMPCORE implementation was not only broken - it would currently
produce a coredump of the tracer process rather than the traced
process - but also deeply flawed, and fixing it would require serious
alteration of PM's internal state machine. It should be possible to
implement the same functionality in userland, and that is now the
suggested way forward. For now, also remove the (identical) utilities
using T_DUMPCORE: dumpcore(1) and gcore(1).
Change-Id: I1d51be19c739362b8a5833de949b76382a1edbcc
Previously, processing of some replies coming from character drivers
could block on locks, and therefore, such processing was done from
threads that were associated to the character driver process. The
hidden consequence of this was that if all threads were in use, VFS
could drop replies coming from the driver. This patch returns VFS to
a situation where the replies from character drivers are processed
instantly from the main thread, by removing the situations that may
cause VFS to block while handling those replies.
- change the locking model for select, so that it will never block
on any processing that happens after the select call has been set
up, in particular processing of character driver select replies;
- clearly mark all select routines that may never block;
- protect against race conditions in do_select as result of the
locking that still does happen there (as is required for pipes);
- also handle select timers from the main thread;
- move processing of character driver replies into device.c.
Change-Id: I4dc8e69f265cbd178de0fbf321d35f58f067cc57
These days, DEV_OPEN calls to character drivers block the calling
thread until completion or failure, and thus never return SUSPEND to
the caller. The same already applied to BDEV_OPEN calls to block
drivers. It has thus become impossible for a process to enter a state
of being blocked on a device open call.
There is currently no support for restarting device open calls to
restarted character drivers. This support was present in the _DOPEN
logic, but was already no longer triggering. In the future, this case
should be handled by the thread performing the open request.
Change-Id: I6cc1e7b4c9ed116c6ce160b315e6e060124dce00
Not doing so caused PFS to commit protocol violations by relying on
stale information when sending replies. This stale information always
happened to be correct, which is why the problem went unnoticed.
Change-Id: Ia42ca670718d6e731193cd2c34a3ff455f8a94d3
- change all sync char drivers into async drivers;
- retire support for the sync protocol in libchardev;
- remove async dev style, as this is now the default;
- remove dev_status from VFS;
- clean up now-unused protocol messages.
Change-Id: I6aacff712292f6b29f2ccd51bc1e7d7003723e87
The async char protocol already has this, so this patch closes the
gap between the two protocols a bit. Support for this flag has been
added to all sync char drivers that support CANCEL at all.
The LOG driver was already using the asynchronous protocol, but it
did not support the nonblocking transfer flag. This has been fixed
as well.
Change-Id: Ia55432c9f102765b59ad3feb45a8bd47a782c93f
As with w_task, this ensures that the field remains cleared if it is
not used. Without this, worker_stop could mistakenly identify a thread
as talking to a device driver rather than a (crashed) file server.
Change-Id: I7d3ebed3efc3cd4f5c891f61c67a6463109b6376
It was always set, but not always cleared, when talking to asynchronous
drivers. This could cause erratic behavior upon a driver crash.
Normally, a worker thread's w_task field is set when it's about to
communicate with a driver or FS. Then upon receiving a reply we can
do sanity checks (that the thread we want to wake up was actually
waiting for a reply). Also, when a driver/FS crashes, we can identify
which worker threads were talking to the crashed endpoint and handle
the error gracefully.
Asynchronous drivers are a bit special, though. In most cases, the
sender of the request is not interested in the reply (the sender was
suspended and only wants to know whether the request was successfully
caried out or not). However, the open request is special, as the reply
carries information needed by the sender. This is the only request
where a worker thread actually yields and waits for the result. This is
also the only case where we're interested in setting w_task for
asynchronous drivers.
Change-Id: Ia1ce2747937df376122b5e13b6a069de27fcc379
* Removed startup code patches in lib/csu regarding kernel to userland
ABI.
* Aligned stack layout on NetBSD stack layout.
* Generate valid stack pointers instead of offsets by taking into account
_minix_kerninfo->kinfo->user_sp.
* Refactored stack generation, by moving part of execve in two
functions {minix_stack_params(), minix_stack_fill()} and using them
in execve(), rs and vm.
* Changed load offset of rtld (ld.so) to:
execi.args.stack_high - execi.args.stack_size - 0xa00000
which is 10MB below the main executable stack.
Change-Id: I839daf3de43321cded44105634102d419cb36cec
The main motivation for this change is that only Loris supports
multithreading, and Loris supports dynamic thread allocation, so the
number of supported threads can be implemented as a bit flag (i.e.,
either 1 or "at least as many as VFS has"). The ABI break obviates the
need to support file system versioning at this time, and several
other aspects are better implemented as flags as well. Other changes:
- replace peek/bpeek test upon mount with FS flag as well;
- mark libsffs as 64-bit file size capable;
- remove old (3.2.1) getdents support.
Change-Id: I313eace9c50ed816656c31cd47d969033d952a03
- pass in file system type through mount(2), and return this type in
statvfs structures as generated by [f]statvfs(2);
- align mount flags field with NetBSD's, splitting out service flags
which are not to be passed to VFS;
- remove limitation of mount ABI to 16-byte labels, so that labels
can be made larger in the future;
- introduce new m11 message union type for mount(2) as side effect.
Change-Id: I88b7710e297e00a5e4582ada5243d3d5c2801fd9
This is a requirement for implementing calls such as getmntinfo(3).
VFS is now responsible for filling in some of the structure's fields.
Change-Id: I0c1fa78019587efefd2949b3be38cd9a7ddc2ced
The following types are modified (old -> new):
* _BSD_USECONDS_T_ int -> unsigned int
* __socklen_t __int32_t -> __uint32_t
* blksize_t uint32_t -> int32_t
* rlim_t uint32_t -> uint64_t
On ARM:
* _BSD_CLOCK_T_ int -> unsigned int
On Intel:
* _BSD_CLOCK_T_ int -> unsigned long
bin/cat is also updated in order to fix warnings.
_BSD_TIMER_T_ has still to be aligned.
Change-Id: I2b4fda024125a19901120546c4e22e443ba5e9d7
clock_t is currently a signed type, but in NetBSD this is not the
case. As we plan on aligning our types we have to change this as this
prevents negative delta from being correctly used.
Change-Id: I9bccdee2b41626b0262471dc1900de505a1991a7
. make filesystems on primary partitions to make it
easier on the minix partition util
. so sfdisk isn't required as an external tool
. also make partition and hitherto x86-only utilities
arch-independent
Change-Id: Ib4e07e45d038d084dde1858917d3deb7f0616532
Before this change overflowing the free running clock counter
between the time the timer was read and the time the overflow
check was done resulted in read_tsc_64 returning a to high value.
Change-Id: I1022f271213647f720477c4121d45f0c965456c6
When we start using a new pagetable (for a new process)
the last part is to ensure the pagetable itself can be
accessed by VM. This is done in pt_bind by updating
the "pagetable of pagetables" and we want this mapping
to match other mappings to the l1 pagetable.
Change-Id: I7b506fd75553917fdc1abd25b55e4b2f25ccbf8d
When copying data from cacheable memory also use cacheable
attributes when creating temporary mappings.
Change-Id: I0e8380293fb4edaafba49f6262983ad86a5350c5
