1. 17 12月, 2010 1 次提交
    • A
      MIPS: Don't stomp on caller's ->regs[2] in copy_thread() · a989ff89
      Al Viro 提交于
      We never needed that (->regs[2] is overwritten on return from syscall paths
      with return value of syscall, so storing it there early made no sense) and
      with new restart logics since d27240bf7e61d2656de18e158ec910a902030847 it
      has become really bad - we lose the original syscall number before the
      place where we decide that we might need a syscall restart.
      
      Note that for child we do need the assignment to regs[2] - it won't go
      through the normal return from syscall path.
      
      [Ralf: Issue found and reported by Lluís; initial investigations by me;
      bug finally found and patch by Al; testing by me and Lluís.]
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      Tested-by: NLluís Batlle i Rossell <viriketo@gmail.com>
      Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      a989ff89
  2. 13 4月, 2010 1 次提交
  3. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  4. 04 8月, 2009 1 次提交
    • D
      MIPS: Avoid clobbering struct pt_regs in kthreads · 484889fc
      David Daney 提交于
      The resume() implementation octeon_switch.S examines the saved cp0_status
      register.  We were clobbering the entire pt_regs structure in kernel
      threads leading to random crashes.
      
      When switching away from a kernel thread, the saved cp0_status is examined
      and if bit 30 is set it is cleared and the CP2 state saved into the pt_regs
      structure.  Since the kernel thread stack overlaid the pt_regs structure
      this resulted in a corrupt stack.  When the kthread with the corrupt stack
      was resumed, it could crash if it used any of the data in the stack that was
      clobbered.
      
      We fix it by moving the kernel thread stack down so it doesn't overlay
      pt_regs.
      Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
      Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      484889fc
  5. 25 6月, 2009 1 次提交
    • R
      MIPS: Add arch generic CPU hotplug · 1b2bc75c
      Ralf Baechle 提交于
      Each platform has to add support for CPU hotplugging itself by providing
      suitable definitions for the cpu_disable and cpu_die of the smp_ops
      methods and setting SYS_SUPPORTS_HOTPLUG_CPU.  A platform should only set
      SYS_SUPPORTS_HOTPLUG_CPU once all it's smp_ops definitions have the
      necessary changes.  This patch contains the changes to the dummy smp_ops
      definition for uni-processor systems.
      
      Parts of the code contributed by Cavium Inc.
      Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      1b2bc75c
  6. 03 4月, 2009 1 次提交
  7. 04 10月, 2008 1 次提交
  8. 21 9月, 2008 1 次提交
  9. 07 9月, 2008 1 次提交
  10. 19 7月, 2008 1 次提交
    • T
      nohz: prevent tick stop outside of the idle loop · b8f8c3cf
      Thomas Gleixner 提交于
      Jack Ren and Eric Miao tracked down the following long standing
      problem in the NOHZ code:
      
      	scheduler switch to idle task
      	enable interrupts
      
      Window starts here
      
      	----> interrupt happens (does not set NEED_RESCHED)
      	      	irq_exit() stops the tick
      
      	----> interrupt happens (does set NEED_RESCHED)
      
      	return from schedule()
      	
      	cpu_idle(): preempt_disable();
      
      Window ends here
      
      The interrupts can happen at any point inside the race window. The
      first interrupt stops the tick, the second one causes the scheduler to
      rerun and switch away from idle again and we end up with the tick
      disabled.
      
      The fact that it needs two interrupts where the first one does not set
      NEED_RESCHED and the second one does made the bug obscure and extremly
      hard to reproduce and analyse. Kudos to Jack and Eric.
      
      Solution: Limit the NOHZ functionality to the idle loop to make sure
      that we can not run into such a situation ever again.
      
      cpu_idle()
      {
      	preempt_disable();
      
      	while(1) {
      		 tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
      		 			          are in the idle loop
      
      		 while (!need_resched())
      		       halt();
      
      		 tick_nohz_restart_sched_tick(); <- disables NOHZ mode
      		 preempt_enable_no_resched();
      		 schedule();
      		 preempt_disable();
      	}
      }
      
      In hindsight we should have done this forever, but ... 
      
      /me grabs a large brown paperbag.
      
      Debugged-by: Jack Ren <jack.ren@marvell.com>, 
      Debugged-by: Neric miao <eric.y.miao@gmail.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      b8f8c3cf
  11. 16 7月, 2008 1 次提交
  12. 15 12月, 2007 1 次提交
  13. 12 10月, 2007 3 次提交
  14. 01 8月, 2007 1 次提交
  15. 21 7月, 2007 1 次提交
  16. 11 7月, 2007 1 次提交
  17. 27 2月, 2007 1 次提交
  18. 19 2月, 2007 2 次提交
  19. 07 2月, 2007 1 次提交
  20. 20 10月, 2006 1 次提交
  21. 10 10月, 2006 1 次提交
  22. 02 10月, 2006 2 次提交
  23. 27 9月, 2006 8 次提交
  24. 01 7月, 2006 1 次提交
  25. 19 4月, 2006 2 次提交
  26. 01 4月, 2006 1 次提交
  27. 21 3月, 2006 1 次提交
  28. 15 2月, 2006 1 次提交