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  1. 15 5月, 2008 1 次提交
  3. 12 5月, 2008 3 次提交
    • L
      Add new 'cond_resched_bkl()' helper function · c3921ab7
      由 Linus Torvalds 提交于 
      It acts exactly like a regular 'cond_resched()', but will not get
optimized away when CONFIG_PREEMPT is set.

Normal kernel code is already preemptable in the presense of
CONFIG_PREEMPT, so cond_resched() is optimized away (see commit
02b67cc3 "sched: do not do
cond_resched() when CONFIG_PREEMPT").

But when wanting to conditionally reschedule while holding a lock, you
need to use "cond_sched_lock(lock)", and the new function is the BKL
equivalent of that.

Also make fs/locks.c use it.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c3921ab7
    • J
      i2c: Convert some more new-style drivers to use module aliasing · ae429083
      由 Jean Delvare 提交于 
      Update 3 more new-style i2c drivers to use standard module aliasing
instead of the old driver_name/type driver matching scheme. These
video drivers aren't used yet so converting them is trivial.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
      ae429083
    • J
      i2c: Match dummy devices by type · 60b129d7
      由 Jean Delvare 提交于 
      As the old driver_name/type matching scheme is going away soon, change
the dummy device mechanism to use the new matching scheme.

This has the downside that dummy i2c clients can no longer choose
their name, they'll all appear as "dummy" in sysfs and in log
messages. I don't think it is a problem in practice though, as there
is little reason to use these i2c clients to log messages.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
      60b129d7
  5. 11 5月, 2008 8 次提交
    • D
      sparc: Fix debugger syscall restart interactions. · 28e61036
      由 David S. Miller 提交于 
      So, forever, we've had this ptrace_signal_deliver implementation
which tries to handle all of the nasties that can occur when the
debugger looks at a process about to take a signal.  It's meant
to address all of these issues inside of the kernel so that the
debugger need not be mindful of such things.

Problem is, this doesn't work.

The idea was that we should do the syscall restart business first, so
that the debugger captures that state.  Otherwise, if the debugger for
example saves the child's state, makes the child execute something
else, then restores the saved state, we won't handle the syscall
restart properly because we lose the "we're in a syscall" state.

The code here worked for most cases, but if the debugger actually
passes the signal through to the child unaltered, it's possible that
we would do a syscall restart when we shouldn't have.

In particular this breaks the case of debugging a process under a gdb
which is being debugged by yet another gdb.  gdb uses sigsuspend
to wait for SIGCHLD of the inferior, but if gdb itself is being
debugged by a top-level gdb we get a ptrace_stop().  The top-level gdb
does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
signal.  But ptrace_signal_deliver() assumed the debugger would cancel
out the signal and therefore did a syscall restart, because the return
error was ERESTARTNOHAND.

Fix this by simply making ptrace_signal_deliver() a nop, and providing
a way for the debugger to control system call restarting properly:

1) Report a "in syscall" software bit in regs->{tstate,psr}.
   It is set early on in trap entry to a system call and is fully
   visible to the debugger via ptrace() and regsets.

2) Test this bit right before doing a syscall restart.  We have
   to do a final recheck right after get_signal_to_deliver() in
   case the debugger cleared the bit during ptrace_stop().

3) Clear the bit in trap return so we don't accidently try to set
   that bit in the real register.

As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
like sparc64 has.

M68K has this same exact bug, and is now the only other user of the
ptrace_signal_deliver hook.  It needs to be fixed in the same exact
way as sparc.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      28e61036
    • D
      sparc: Fix ptrace() detach. · 986bef85
      由 David S. Miller 提交于 
      Forever we had a PTRACE_SUNOS_DETACH which was unconditionally
recognized, regardless of the personality of the process.

Unfortunately, this value is what ended up in the GLIBC sys/ptrace.h
header file on sparc as PTRACE_DETACH and PT_DETACH.

So continue to recognize this old value.  Luckily, it doesn't conflict
with anything we actually care about.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      986bef85
    • L
      BKL: revert back to the old spinlock implementation · 8e3e076c
      由 Linus Torvalds 提交于 
      The generic semaphore rewrite had a huge performance regression on AIM7
(and potentially other BKL-heavy benchmarks) because the generic
semaphores had been rewritten to be simple to understand and fair.  The
latter, in particular, turns a semaphore-based BKL implementation into a
mess of scheduling.

The attempt to fix the performance regression failed miserably (see the
previous commit 00b41ec2 'Revert
"semaphore: fix"'), and so for now the simple and sane approach is to
instead just go back to the old spinlock-based BKL implementation that
never had any issues like this.

This patch also has the advantage of being reported to fix the
regression completely according to Yanmin Zhang, unlike the semaphore
hack which still left a couple percentage point regression.

As a spinlock, the BKL obviously has the potential to be a latency
issue, but it's not really any different from any other spinlock in that
respect.  We do want to get rid of the BKL asap, but that has been the
plan for several years.

These days, the biggest users are in the tty layer (open/release in
particular) and Alan holds out some hope:

  "tty release is probably a few months away from getting cured - I'm
   afraid it will almost certainly be the very last user of the BKL in
   tty to get fixed as it depends on everything else being sanely locked."

so while we're not there yet, we do have a plan of action.
Tested-by: NYanmin Zhang <yanmin_zhang@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Alexander Viro <viro@ftp.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8e3e076c
    • L
      Make <asm-x86/spinlock.h> use ACCESS_ONCE() · 39f004ba
      由 Linus Torvalds 提交于 
      ..instead of cooking up its own uglier local version of it.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      39f004ba
    • L
      Move ACCESS_ONCE() to <linux/compiler.h> · 9c3cdc1f
      由 Linus Torvalds 提交于 
      It actually makes much more sense there, and we do tend to need it for
non-RCU usage too.  Moving it to <linux/compiler.h> will allow some
other cases that have open-coded the same logic to use the same helper
function that RCU has used.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9c3cdc1f
    • V
      x86: sysfs cpu?/topology is empty in 2.6.25 (32-bit Intel system) · 5c3a121d
      由 Vaidyanathan Srinivasan 提交于 
      System topology on intel based system needs to be exported
for non-numa case as well.

All parts of asm-i386/topology.h has come under
#ifdef CONFIG_NUMA after the merge to asm-x86/topology.h

/sys/devices/system/cpu/cpu?/topology/* is populated based on
ENABLE_TOPO_DEFINES

The sysfs cpu topology is not being populated on my dual socket
dual core xeon 5160 processor based (x86 32 bit) system.

CONFIG_NUMA is not set in my case yet the topology is relevant
and useful.

irqbalance daemon application depends on topology to build the
cpus and package list and it fails on Fedora9 beta since the
sysfs topology was not being populated in the 2.6.25 kernel.

I am not sure if it was intentional to not define ENABLE_TOPO_DEFINES
for non-numa systems.

This fix has been tested on the above mentioned dual core, dual socket
system.
Signed-off-by: NVaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
      5c3a121d
    • S
      x86: revert commit 709f744f ("x86: bitops asm constraint fixes") · eb2b4e68
      由 Simon Holm Thøgersen 提交于 
      709f744f causes my computer to freeze during the start up of X and my
login manger (GDM). It gets to the point where it has shown the default
X mouse cursor logo (a big X / cross) and does not respond to anything
from that point on.

This worked fine before 709f744f, and it works fine with 709f744f
reverted on top of Linus' current tree (f74d505b). The revert had
conflicts, as far as I can tell due to white space changes. The diff I
ended up with is below.

It is 100% reproducible.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      eb2b4e68
    • S
      x86: fix fpu restore from sig return · fd3c3ed5
      由 Suresh Siddha 提交于 
      If the task never used fpu, initialize the fpu before restoring the FP
state from the signal handler context. This will allocate the fpu
state, if the task never needed it before.
Reported-and-bisected-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Tested-by: NEric Sesterhenn <snakebyte@gmx.de>
Cc: Frederik Deweerdt <deweerdt@free.fr>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      fd3c3ed5
  7. 10 5月, 2008 1 次提交
  9. 09 5月, 2008 5 次提交
  11. 08 5月, 2008 11 次提交
  13. 07 5月, 2008 9 次提交
  15. 10 5月, 2008 1 次提交
  17. 07 5月, 2008 1 次提交