most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.
Tested on: i386, alpha, sparc64
they aren't in the usual path of execution for syscalls and traps.
The main complication for this is that we have to set flags to control
ast() everywhere that changes the signal mask.
Avoid locking in userret() in most of the remaining cases.
Submitted by: luoqi (first part only, long ago, reorganized by me)
Reminded by: dillon
various machdep.c's to being declared in kern_mutex.c.
- Add a new function mutex_init() used to perform early initialization
needed for mutexes such as setting up thread0's contested lock list
and initializing MI mutexes. Change the various MD startup routines
to call this function instead of duplicating all the code themselves.
Tested on: alpha, i386
and cpu_critical_exit() and moves associated critical prototypes into their
own header file, <arch>/<arch>/critical.h, which is only included by the
three MI source files that need it.
Backout and re-apply improperly comitted syntactical cleanups made to files
that were still under active development. Backout improperly comitted program
structure changes that moved localized declarations to the top of two
procedures. Partially re-apply one of the program structure changes to
move 'mask' into an intermediate block rather then in three separate
sub-blocks to make the code more readable. Re-integrate bug fixes that Jake
made to the sparc64 code.
Note: In general, developers should not gratuitously move declarations out
of sub-blocks. They are where they are for reasons of structure, grouping,
readability, compiler-localizability, and to avoid developer-introduced bugs
similar to several found in recent years in the VFS and VM code.
Reviewed by: jake
general cleanup of the API. The entire API now consists of two functions
similar to the pre-KSE API. The suser() function takes a thread pointer
as its only argument. The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0. The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.
Discussed on: smp@
back into the calling MD code. The MD code must ensure no races between
checking the astpening flag and returning to usermode.
Submitted by: peter (ia64 bits)
Tested on: alpha (peter, jeff), i386, ia64 (peter), sparc64
with this flag. Remove the dup_list and dup_ok code from subr_witness. Now
we just check for the flag instead of doing string compares.
Also, switch the process lock, process group lock, and uma per cpu locks over
to this interface. The original mechanism did not work well for uma because
per cpu lock names are unique to each zone.
Approved by: jhb
disablement assumptions in kern_fork.c by adding another API call,
cpu_critical_fork_exit(). Cleanup the td_savecrit field by moving it
from MI to MD. Temporarily move cpu_critical*() from <arch>/include/cpufunc.h
to <arch>/<arch>/critical.c (stage-2 will clean this up).
Implement interrupt deferral for i386 that allows interrupts to remain
enabled inside critical sections. This also fixes an IPI interlock bug,
and requires uses of icu_lock to be enclosed in a true interrupt disablement.
This is the stage-1 commit. Stage-2 will occur after stage-1 has stabilized,
and will move cpu_critical*() into its own header file(s) + other things.
This commit may break non-i386 architectures in trivial ways. This should
be temporary.
Reviewed by: core
Approved by: core
Instead of caching the ucred reference, just go ahead and eat the
decerement and increment of the refcount. Now that Giant is pushed down
into crfree(), we no longer have to get Giant in the common case. In the
case when we are actually free'ing the ucred, we would normally free it on
the next kernel entry, so the cost there is not new, just in a different
place. This also removse td_cache_ucred from struct thread. This is
still only done #ifdef DIAGNOSTIC.
Tested on: i386, alpha
o In i386's <machine/endian.h>, macros have some advantages over
inlines, so change some inlines to macros.
o In i386's <machine/endian.h>, ungarbage collect word_swap_int()
(previously __uint16_swap_uint32), it has some uses on i386's with
PDP endianness.
Submitted by: bde
o Move a comment up in <machine/endian.h> that was accidentially moved
down a few revisions ago.
o Reenable userland's use of optimized inline-asm versions of
byteorder(3) functions.
o Fix ordering of prototypes vs. redefinition of byteorder(3)
functions, so that the non-GCC (libc asm) case has proper
prototypes.
o Add proper prototypes for byteorder(3) functions in <sys/param.h>.
o Prevent redundant duplicate prototypes by making use of the
_BYTEORDER_PROTOTYPED define.
o Move the bswap16(), bswap32(), bswap64() C functions into MD space
for platforms in which asm versions don't exist. This significantly
reduces the complexity of some things at the cost of duplicate code.
Reviewed by: bde
be allocated as arrays indexed by the cpu id. Previously the only reliable
way to know the max cpu id was through MAXCPU. mp_ncpus isn't useful here
because cpu ids may be sparsely mapped, although x86 and alpha do not do this.
Also, call cpu_mp_probe much earlier so the max cpu id is known before the VM
starts up. This is intended to help support per cpu queues for the new
allocator, but may be useful elsewhere.
Reviewed by: jake
Approved by: jake
Previously, the UPAGES/KSTACK area of processes/threads would leak memory
at the time that a previously swapped process was terminated. Lukcily, the
leak was only 12K/proc, so it was unlikely to be a major problem unless you
had an undersized swap partition.
Submitted by: dillon
Reviewed by: silby
MFC after: 1 week
In order to determine what to page out, the vm_daemon checks
reference bits on all pages belonging to all processes. Unfortunately,
the algorithm used reacted badly with shared pages; each shared page
would be checked once per process sharing it; this caused an O(N^2)
growth of tlb invalidations. The algorithm has been changed so that
each page will be checked only 16 times.
Prior to this change, a fork/sleepbomb of 1300 processes could cause
the vm_daemon to take over 60 seconds to complete, effectively
freezing the system for that time period. With this change
in place, the vm_daemon completes in less than a second. Any system
with hundreds of processes sharing pages should benefit from this change.
Note that the vm_daemon is only run when the system is under extreme
memory pressure. It is likely that many people with loaded systems saw
no symptoms of this problem until they reached the point where swapping
began.
Special thanks go to dillon, peter, and Chuck Cranor, who helped me
get up to speed with vm internals.
PR: 33542, 20393
Reviewed by: dillon
MFC after: 1 week
