* Optimise the return path for syscalls so that they only restore a minimal
set of registers instead of performing a full exception_return.
A new flag in the trapframe indicates that the frame only holds partial
state. When it is necessary to perform a full state restore (e.g. after an
execve or signal), the flag is cleared to force a full restore.
striped plexes. This prevents various panics introduced in the last
rewrite of the locking code.
Suffered by: "Niels Chr. Bank-Pedersen" <ncbp@bank-pedersen.dk>
The PR also included documentation for other options, but upon
inspection of the source these options aren't used.
PR: docs/24149
Submitted by: Jesse Monroy, Jr. <opentrax@email.com>
- If possible, context switch to the thread directly in sched_ithd(),
rather than triggering a delayed ast reschedule.
- Disable interrupts while restoring fpu state in the trap handler,
in order to ensure that we are not preempted in the middle, which
could cause migration to another cpu.
Reviewed by: peter
Tested by: peter (alpha)
field, so it was possible for a filesystem marked clean by fsck_ffs
to cause kernel crashes later when mounted. This could occur when
fsck_ffs was used to repair a badly corrupted filesystem.
As pointed out by bde, it is not sufficient to restrict di_size to
just the superblock fs_maxfilesize limit. The use of 32-bit logical
block numbers (both in fsck and the kernel) induces another file
size limit which is usually lower than fs_maxfilesize. Also, the
old 4.3BSD filesystem does not have fs_maxfilesize initialised.
Following this change, fsck_ffs will enforce exactly the same
file size limits as are used by the kernel.
PR: kern/15065
Discussed with: bde
Reviewed by: bde, mckusick
* Optimise the return path for syscalls so that they only restore a minimal
set of registers instead of performing a full exception_return.
A new flag in the trapframe indicates that the frame only holds partial
state. When it is necessary to perform a full state restore (e.g. after an
execve or signal), the flag is cleared to force a full restore.
Turn off semaphores. Nobody else implements them, and there is lots of
AML out there which does totally absurd things with them, meaning that
if we try to do the right thing we are guaranteed to fail.
