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  1. 26 1月, 2008 5 次提交
  3. 25 1月, 2008 8 次提交
  5. 11 1月, 2008 3 次提交
  7. 04 12月, 2007 2 次提交
  9. 20 11月, 2007 8 次提交
  11. 10 11月, 2007 1 次提交
    • P
      sched: restore deterministic CPU accounting on powerpc · fa13a5a1
      由 Paul Mackerras 提交于 
      Since powerpc started using CONFIG_GENERIC_CLOCKEVENTS, the
deterministic CPU accounting (CONFIG_VIRT_CPU_ACCOUNTING) has been
broken on powerpc, because we end up counting user time twice: once in
timer_interrupt() and once in update_process_times().

This fixes the problem by pulling the code in update_process_times
that updates utime and stime into a separate function called
account_process_tick.  If CONFIG_VIRT_CPU_ACCOUNTING is not defined,
there is a version of account_process_tick in kernel/timer.c that
simply accounts a whole tick to either utime or stime as before.  If
CONFIG_VIRT_CPU_ACCOUNTING is defined, then arch code gets to
implement account_process_tick.

This also lets us simplify the s390 code a bit; it means that the s390
timer interrupt can now call update_process_times even when
CONFIG_VIRT_CPU_ACCOUNTING is turned on, and can just implement a
suitable account_process_tick().

account_process_tick() now takes the task_struct * as an argument.
Tested both with and without CONFIG_VIRT_CPU_ACCOUNTING.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      fa13a5a1
  13. 05 11月, 2007 4 次提交
  15. 31 10月, 2007 1 次提交
  17. 22 10月, 2007 8 次提交
    • M
      [S390] 4level-fixup cleanup · 190a1d72
      由 Martin Schwidefsky 提交于 
      Get independent from asm-generic/4level-fixup.h
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      190a1d72
    • M
      [S390] Cleanup page table definitions. · 3610cce8
      由 Martin Schwidefsky 提交于 
      - De-confuse the defines for the address-space-control-elements
  and the segment/region table entries.
- Create out of line functions for page table allocation / freeing.
- Simplify get_shadow_xxx functions.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      3610cce8
    • M
      [S390] Introduce follow_table in uaccess_pt.c · e4aa402e
      由 Martin Schwidefsky 提交于 
      Define and use follow_table inline in uaccess_pt.c to simplify
the code.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      e4aa402e
    • M
      [S390] Remove unused user_seg from thread structure. · 6f3fa3f0
      由 Martin Schwidefsky 提交于 
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      6f3fa3f0
    • M
      [S390] tlb flush fix. · ba8a9229
      由 Martin Schwidefsky 提交于 
      The current tlb flushing code for page table entries violates the
s390 architecture in a small detail. The relevant section from the
principles of operation (SA22-7832-02 page 3-47):

   "A valid table entry must not be changed while it is attached
   to any CPU and may be used for translation by that CPU except to
   (1) invalidate the entry by using INVALIDATE PAGE TABLE ENTRY or
   INVALIDATE DAT TABLE ENTRY, (2) alter bits 56-63 of a page-table
   entry, or (3) make a change by means of a COMPARE AND SWAP AND
   PURGE instruction that purges the TLB."

That means if one thread of a multithreaded applciation uses a vma
while another thread does an unmap on it, the page table entries of
that vma needs to get removed with IPTE, IDTE or CSP. In some strange
and rare situations a cpu could check-stop (die) because a entry has
been pushed out of the TLB that is still needed to complete a
(milli-coded) instruction. I've never seen it happen with the current
code on any of the supported machines, so right now this is a
theoretical problem. But I want to fix it nevertheless, to avoid
headaches in the futures.

To get this implemented correctly without changing common code the
primitives ptep_get_and_clear, ptep_get_and_clear_full and
ptep_set_wrprotect need to use the IPTE instruction to invalidate the
pte before the new pte value gets stored. If IPTE is always used for
the three primitives three important operations will have a performace
hit: fork, mprotect and exit_mmap. Time for some workarounds:

* 1: ptep_get_and_clear_full is used in unmap_vmas to remove page
tables entries in a batched tlb gather operation. If the mmu_gather
context passed to unmap_vmas has been started with full_mm_flush==1
or if only one cpu is online or if the only user of a mm_struct is the
current process then the fullmm indication in the mmu_gather context is
set to one. All TLBs for mm_struct are flushed by the tlb_gather_mmu
call. No new TLBs can be created while the unmap is in progress. In
this case ptep_get_and_clear_full clears the ptes with a simple store.

* 2: ptep_get_and_clear is used in change_protection to clear the
ptes from the page tables before they are reentered with the new
access flags. At the end of the update flush_tlb_range clears the
remaining TLBs. In general the ptep_get_and_clear has to issue IPTE
for each pte and flush_tlb_range is a nop. But if there is only one
user of the mm_struct then ptep_get_and_clear uses simple stores
to do the update and flush_tlb_range will flush the TLBs.

* 3: Similar to 2, ptep_set_wrprotect is used in copy_page_range
for a fork to make all ptes of a cow mapping read-only. At the end of
of copy_page_range dup_mmap will flush the TLBs with a call to
flush_tlb_mm.  Check for mm->mm_users and if there is only one user
avoid using IPTE in ptep_set_wrprotect and let flush_tlb_mm clear the
TLBs.

Overall for single threaded programs the tlb flush code now performs
better, for multi threaded programs it is slightly worse. In particular
exit_mmap() now does a single IDTE for the mm and then just frees every
page cache reference and every page table page directly without a delay
over the mmu_gather structure.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      ba8a9229
    • M
      [S390] kernel: Fix dump on panic for DASDs under LPAR. · e3d3683d
      由 Michael Holzheu 提交于 
      Currently the ccw method is used to ipl the DASD dump record under LPAR.
This mechanism is not reliable, which can cause dump failures. This fix
now uses the diag 308 ipl method for all machines, which have diag308
subcode 5 and 4 support.
Signed-off-by: NMichael Holzheu <holzheu@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      e3d3683d
    • H
      [S390] Add per-cpu idle time / idle count sysfs attributes. · fae8b22d
      由 Heiko Carstens 提交于 
      Add two new sysfs entries per cpu: idle_count and idle_time.
idle_count contains the number of times a cpu went into idle state.
idle_time contains the time a cpu spent in idle state in microseconds.
This can be used e.g. by powertop to tell how often idle state is
entered and left.

# cat /sys/devices/system/cpu/cpu0/idle_count
504
# cat /sys/devices/system/cpu/cpu0/idle_time
469734037 us

Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      fae8b22d
    • M
      [S390] Update default configuration. · 32346f47
      由 Martin Schwidefsky 提交于 
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      32346f47