volatile so that the compiler won't perform CSE. For SMP,
this may result in us accessing the wrong PCPU and as such
results in a bogus curthread value.
Note that getting curthread is not quite MP-safe in the sense
that it requires two instructions that aren't performed
atomically. The first instruction gets the address of the PCPU
structure and the second instruction dereferences that pointer
to get curthread. If a thread is switched-out in between these
instructions and switched-in on a different CPU, we still get
the wrong curthread.
cap on memory usage, then shared LOOKUP operations could start free'ing
dirhash structures. Without these fixes, concurrent free's on the same
directory could result in one of the threads blocked on a lock in a dirhash
structure free'd by the other thread.
- Replace the lockmgr lock in the dirhash structure with an sx lock.
- Use a reference count managed with ufsdirhash_hold()/drop() to determine
when to free the dirhash structures. The directory i-node holds a
reference while the dirhash is attached to an i-node. Code that wishes
to lock the dirhash while holding a shared vnode lock must first
acquire a private reference to the dirhash while holding the vnode
interlock before acquiring the dirhash sx lock. After acquiring the sx
lock, it drops the private reference after checking to see if the
dirhash is still used by the directory i-node.
non-LOOKUP operations.
- Relax a VOP assertion for a DELETE lookup. rename() uses WANTPARENT
instead of LOCKPARENT when looking up the source pathname. ufs_rename()
uses a relookup() to lock the parent directory when it decides to finally
remove the source path. Thus, it is ok for a DELETE with WANTPARENT set
instead of LOCKPARENT to use a shared vnode lock rather than an exclusive
vnode lock.
Reported by: kris (2)
Reviewed by: jeff
upgrades the vnode lock if it is share locked was dropping the interlock
before actually checking VI_DOOMED. Fix this by do the vdropl() after the
check and relying on it to drop the vnode interlock.
Reported by: pho
Reviewed by: kib
MFC after: 1 week
Unlike tty_rel_gone() and tty_rel_sess(), the tty_rel_pgrp() routine
does not unlock the TTY. I once had the idea to make the code call
tty_rel_pgrp() and tty_rel_sess(), picking up the TTY lock once. This
turned out a little harder than I expected, so this is how it works now.
It's a lot easier if we just let tty_rel_pgrp() unlock the TTY, because
the other routines do this anyway.
wait until the current suspension is lifted instead of silently returning
success immediately. The consequences of calling vfs_write() resume when
not owning the suspension are not well-defined at best.
Add the vfs_susp_clean() mount method to be called from
vfs_write_resume(). Set it to process_deferred_inactive() for ffs, and
stop calling it manually.
Add the thread flag TDP_IGNSUSP that allows to bypass the suspension
point in the vn_start_write. It is intended for use by VFS in the
situations where the suspender want to do some i/o requiring calls to
vn_start_write(), and this i/o cannot be done later.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
Show the b_dep value for the buffer in the show buffer command.
Add a comand to dump the dirty/clean buffer list for vnode.
Reviewed by: tegge
Tested and used by: pho
MFC after: 1 month
MNT_RDONLY flag before the VFS_MOUNT() is called. In ufs_inactive()
and ufs_itimes_locked(), UFS verifies whether the fs is read-only by
checking MNT_RDONLY, but this may cause loss of the IN_MODIFIED flag
for inode on the fs being remounted rw->ro.
Introduce UFS_RDONLY() struct ufsmount' method that reports the value
of the fs_ronly. The later is set to 1 only after the remount is
finished.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
inode having number ino. In r170991, the ip was marked IN_MODIFIED, that
is not quite correct.
Mark only the right inode modified by checking inode number.
Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month
bit flag, otherwise if a thread acquired a lock, another thread
or the current thread itself can no longer acquire another lock
because thread_mask_set() return whole flag word, this results
bit leaking in the word and misbehavior in later locking and
unlocking.
the command set (only so long as the module is present):
o add db_command_register and db_command_unregister to add and remove
commands, respectively
o replace linker sets with SYSINIT's (and SYSUINIT's) that register
commands
o expose 3 list heads: db_cmd_table, db_show_table, and db_show_all_table
for registering top-level commands, show operands, and show all operands,
respectively
While here also:
o sort command lists
o add DB_ALIAS, DB_SHOW_ALIAS, and DB_SHOW_ALL_ALIAS to add aliases
for existing commands
o add "show all trace" as an alias for "show alltrace"
o add "show all locks" as an alias for "show alllocks"
Submitted by: Guillaume Ballet <gballet@gmail.com> (original version)
Reviewed by: jhb
MFC after: 1 month
- Retire IVARs for passing IRQs around. Instead, ppbus and ppc now allow
child devices to access the interrupt by via a rid 0 IRQ resource
using bus_alloc_resource_any().
- ppc creates its own interrupt event to manage the interrupt handlers of
child devices. ppc does not allow child devices to use filters. It
could allow this if needed, but none of the current drivers use them
and it adds a good bit of complication. It uses
intr_event_execute_handlers() to fire the child device interrupt handlers
from its threaded interrupt handler.
- Remove the ppbus_dummy_intr() hack. Now the ppc device always has an
interrupt handler registered and we no longer bounce all the way up to
nexus to manage adding/removing ppbus child interrupt handlers. Instead,
the child handlers are added and removed to the private interrupt event
in the ppc device.
all the non-filter handlers attached to an interrupt event. This can be
used by device drivers which multiplex their interrupt onto the interrupt
handlers for child devices.
It seems we only depend on COMPAT_43 to implement the send() and recv()
routines. We can easily implement them using sendto() and recvfrom(),
just like we do inside our very own C library.
I wasn't able to really test it, apart from simple compilation testing.
I've heard rumours that COMPAT_SVR4 is broken inside execve() anyway.
It's still worth to fix this, because I suspect we'll get rid of
COMPAT_43 somewhere in the future...
Reviewed by: rdivacky
Discussed with: jhb
On the i386 architecture, the processor only saves the current value
of `%esp' on stack if a privilege switch is necessary when entering
the interrupt handler. Thus, `frame->tf_esp' is only valid for
an entry from user mode. For interrupts taken in kernel mode, we
need to determine the top-of-stack for the interrupted kernel
procedure by adding the appropriate offset to the current frame
pointer.
Reported by: kris, Fabien Thomas
Tested by: Fabien Thomas <fabien.thomas at netasq dot com>
someone else might change it, so after we re-acquire the lock on it,
we need to check it is still valid. People have been panicing in this
function due to soem edge cases which I have hopefully removed.
Reviewed by: keramida @
Obtained from: 1 week
common PowerPC code when all we want to achieve is to enable
external interrupts. We can set PSL_RI at any time before we
allow interrupts and/or exceptions, so move it to the AIM
specific initialization and do it when we also set PSL_ME
(machine check enable).
configuring the L2 cache on the BSP. Nor the L3 cache. We
merely print the settings.
Save the L2 and L3 cache configuration in global values so
that we know how to configure the cache on APs.
ABI change on ILP32 platforms and relating to events. However
it's harmless on little-endian ILP32 platforms in the sense
that it doesn't cause breakages. Old ILP32 thread libraries
write a 32-bit th_p and new thread libraries write a 64-bit
th_p. But due to the fact that we have an unused 32-bit data
field right after th_p and that field is always initialized to
zero, little-endian ILP32 machines effectively have a valid
64-bit th_p by accident. Likewise for new thread libraries and
old libthread_db: little endian ILP32 is unaffected.
At this time we don't support big-endian threaded applications
in GDB, so the breakage for the ILP32 case goes unnoticed.
