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  1. 28 1月, 2013 1 次提交
    • F
      cputime: Generic on-demand virtual cputime accounting · abf917cd
      由 Frederic Weisbecker 提交于 
      If we want to stop the tick further idle, we need to be
able to account the cputime without using the tick.

Virtual based cputime accounting solves that problem by
hooking into kernel/user boundaries.

However implementing CONFIG_VIRT_CPU_ACCOUNTING require
low level hooks and involves more overhead. But we already
have a generic context tracking subsystem that is required
for RCU needs by archs which plan to shut down the tick
outside idle.

This patch implements a generic virtual based cputime
accounting that relies on these generic kernel/user hooks.

There are some upsides of doing this:

- This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING
if context tracking is already built (already necessary for RCU in full
tickless mode).

- We can rely on the generic context tracking subsystem to dynamically
(de)activate the hooks, so that we can switch anytime between virtual
and tick based accounting. This way we don't have the overhead
of the virtual accounting when the tick is running periodically.

And one downside:

- There is probably more overhead than a native virtual based cputime
accounting. But this relies on hooks that are already set anyway.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
      abf917cd
  3. 10 7月, 2012 7 次提交
  5. 30 4月, 2012 1 次提交
  7. 09 3月, 2012 1 次提交
  9. 12 7月, 2011 1 次提交
  11. 20 4月, 2011 1 次提交
  13. 02 9月, 2010 1 次提交
    • P
      powerpc: Account time using timebase rather than PURR · cf9efce0
      由 Paul Mackerras 提交于 
      Currently, when CONFIG_VIRT_CPU_ACCOUNTING is enabled, we use the
PURR register for measuring the user and system time used by
processes, as well as other related times such as hardirq and
softirq times.  This turns out to be quite confusing for users
because it means that a program will often be measured as taking
less time when run on a multi-threaded processor (SMT2 or SMT4 mode)
than it does when run on a single-threaded processor (ST mode), even
though the program takes longer to finish.  The discrepancy is
accounted for as stolen time, which is also confusing, particularly
when there are no other partitions running.

This changes the accounting to use the timebase instead, meaning that
the reported user and system times are the actual number of real-time
seconds that the program was executing on the processor thread,
regardless of which SMT mode the processor is in.  Thus a program will
generally show greater user and system times when run on a
multi-threaded processor than on a single-threaded processor.

On pSeries systems on POWER5 or later processors, we measure the
stolen time (time when this partition wasn't running) using the
hypervisor dispatch trace log.  We check for new entries in the
log on every entry from user mode and on every transition from
kernel process context to soft or hard IRQ context (i.e. when
account_system_vtime() gets called).  So that we can correctly
distinguish time stolen from user time and time stolen from system
time, without having to check the log on every exit to user mode,
we store separate timestamps for exit to user mode and entry from
user mode.

On systems that have a SPURR (POWER6 and POWER7), we read the SPURR
in account_system_vtime() (as before), and then apportion the SPURR
ticks since the last time we read it between scaled user time and
scaled system time according to the relative proportions of user
time and system time over the same interval.  This avoids having to
read the SPURR on every kernel entry and exit.  On systems that have
PURR but not SPURR (i.e., POWER5), we do the same using the PURR
rather than the SPURR.

This disables the DTL user interface in /sys/debug/kernel/powerpc/dtl
for now since it conflicts with the use of the dispatch trace log
by the time accounting code.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      cf9efce0
  15. 28 8月, 2009 1 次提交
  17. 20 8月, 2009 1 次提交
  19. 21 5月, 2009 1 次提交
  21. 28 4月, 2009 1 次提交
  23. 23 2月, 2009 1 次提交
    • K
      powerpc: Unify opcode definitions and support · 16c57b36
      由 Kumar Gala 提交于 
      Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.

We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.

Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      16c57b36
  25. 23 12月, 2008 1 次提交
  27. 16 9月, 2008 1 次提交
    • P
      powerpc: Use LOAD_REG_IMMEDIATE only for constants on 64-bit · e31aa453
      由 Paul Mackerras 提交于 
      Using LOAD_REG_IMMEDIATE to get the address of kernel symbols
generates 5 instructions where LOAD_REG_ADDR can do it in one,
and will generate R_PPC64_ADDR16_* relocations in the output when
we get to making the kernel as a position-independent executable,
which we'd rather not have to handle.  This changes various bits
of assembly code to use LOAD_REG_ADDR when we need to get the
address of a symbol, or to use suitable position-independent code
for cases where we can't access the TOC for various reasons, or
if we're not running at the address we were linked at.

It also cleans up a few minor things; there's no reason to save and
restore SRR0/1 around RTAS calls, __mmu_off can get the return
address from LR more conveniently than the caller can supply it in
R4 (and we already assume elsewhere that EA == RA if the MMU is on
in early boot), and enable_64b_mode was using 5 instructions where
2 would do.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      e31aa453
  29. 04 8月, 2008 1 次提交
  31. 01 7月, 2008 2 次提交
  33. 23 5月, 2008 1 次提交
  35. 14 9月, 2007 1 次提交
    • K
      [POWERPC] Fix modpost warnings from head*.S on ppc32 · 748a7683
      由 Kumar Gala 提交于 
      We get warnings like the following from the various ppc32 head*.S files:

WARNING: vmlinux.o(.text+0x358): Section mismatch: reference to .init.text:early_init (between 'skpinv' and 'interrupt_base')
WARNING: vmlinux.o(.text+0x380): Section mismatch: reference to .init.text:machine_init (between 'skpinv' and 'interrupt_base')
WARNING: vmlinux.o(.text+0x384): Section mismatch: reference to .init.text:MMU_init (between 'skpinv' and 'interrupt_base')
WARNING: vmlinux.o(.text+0x3aa): Section mismatch: reference to .init.text:start_kernel (between 'skpinv' and 'interrupt_base')
WARNING: vmlinux.o(.text+0x3ae): Section mismatch: reference to .init.text:start_kernel (between 'skpinv' and 'interrupt_base')

Added a .text.head section simliar to what other architectures do since
modpost already excludes this from its warnings.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
      748a7683
  37. 22 8月, 2007 1 次提交
  39. 26 7月, 2007 1 次提交
  41. 25 10月, 2006 1 次提交
  43. 26 4月, 2006 1 次提交
  45. 24 2月, 2006 1 次提交
    • P
      powerpc: Implement accurate task and CPU time accounting · c6622f63
      由 Paul Mackerras 提交于 
      This implements accurate task and cpu time accounting for 64-bit
powerpc kernels.  Instead of accounting a whole jiffy of time to a
task on a timer interrupt because that task happened to be running at
the time, we now account time in units of timebase ticks according to
the actual time spent by the task in user mode and kernel mode.  We
also count the time spent processing hardware and software interrupts
accurately.  This is conditional on CONFIG_VIRT_CPU_ACCOUNTING.  If
that is not set, we do tick-based approximate accounting as before.

To get this accurate information, we read either the PURR (processor
utilization of resources register) on POWER5 machines, or the timebase
on other machines on

* each entry to the kernel from usermode
* each exit to usermode
* transitions between process context, hard irq context and soft irq
  context in kernel mode
* context switches.

On POWER5 systems with shared-processor logical partitioning we also
read both the PURR and the timebase at each timer interrupt and
context switch in order to determine how much time has been taken by
the hypervisor to run other partitions ("steal" time).  Unfortunately,
since we need values of the PURR on both threads at the same time to
accurately calculate the steal time, and since we can only calculate
steal time on a per-core basis, the apportioning of the steal time
between idle time (time which we ceded to the hypervisor in the idle
loop) and actual stolen time is somewhat approximate at the moment.

This is all based quite heavily on what s390 does, and it uses the
generic interfaces that were added by the s390 developers,
i.e. account_system_time(), account_user_time(), etc.

This patch doesn't add any new interfaces between the kernel and
userspace, and doesn't change the units in which time is reported to
userspace by things such as /proc/stat, /proc/<pid>/stat, getrusage(),
times(), etc.  Internally the various task and cpu times are stored in
timebase units, but they are converted to USER_HZ units (1/100th of a
second) when reported to userspace.  Some precision is therefore lost
but there should not be any accumulating error, since the internal
accumulation is at full precision.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      c6622f63
  47. 13 1月, 2006 1 次提交
    • D
      [PATCH] powerpc: Cleanup LOADADDR etc. asm macros · e58c3495
      由 David Gibson 提交于 
      This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*).  The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation.  The new macros and their semantics are described in the
comments in ppc_asm.h.

In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC.  Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      e58c3495
  49. 09 1月, 2006 1 次提交
  51. 10 11月, 2005 1 次提交
    • D
      [PATCH] powerpc: Consolidate asm compatibility macros · 3ddfbcf1
      由 David Gibson 提交于 
      This patch consolidates macros used to generate assembly for
compatibility across different CPUs or configs.  A new header,
asm-powerpc/asm-compat.h contains the main compatibility macros.  It
uses some preprocessor magic to make the macros suitable both for use
in .S files, and in inline asm in .c files.  Headers (bitops.h,
uaccess.h, atomic.h, bug.h) which had their own such compatibility
macros are changed to use asm-compat.h.

ppc_asm.h is now for use in .S files *only*, and a #error enforces
that.  As such, we're a lot more careless about namespace pollution
here than in asm-compat.h.

While we're at it, this patch adds a call to the PPC405_ERR77 macro in
futex.h which should have had it already, but didn't.

Built and booted on pSeries, Maple and iSeries (ARCH=powerpc).  Built
for 32-bit powermac (ARCH=powerpc) and Walnut (ARCH=ppc).
Signed-off-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      3ddfbcf1
  53. 02 11月, 2005 1 次提交
    • D
      [PATCH] powerpc: Merge futex.h · 2ff2ae7a
      由 David Gibson 提交于 
      This patch merges the ppc32 and ppc64 versions of futex.h, essentially
by taking the ppc64 version as the powerpc version.  The old ppc32
version did not implement the futex_atomic_op_inuser() callback (it
always returned -ENOSYS), so FUTEX_WAKE_OP would not work on ppc32.
In fact the ppc64 version of this function is almost suitable for
ppc32 as well - the only change needed is to extend ppc_asm.h with a
macro expanding to to the right pseudo-op to store a pointer (either
".long" or ".llong").

Built and booted on pSeries.  Built for 32-bit powermac.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      2ff2ae7a
  55. 28 10月, 2005 1 次提交
    • P
      powerpc: Merge xmon · f78541dc
      由 Paul Mackerras 提交于 
      The merged version follows the ppc64 version pretty closely mostly,
and in fact ARCH=ppc64 now uses the arch/powerpc/xmon version.
The main difference for ppc64 is that the 'p' command to call
show_state (which was always pretty dodgy) has been replaced by
the ppc32 'p' command, which calls a given procedure (so in fact
the old 'p' command behaviour can be achieved with 'p $show_state').
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      f78541dc
  57. 27 10月, 2005 1 次提交
    • P
      powerpc: Introduce toreal/fromreal assembly macros · 6316222e
      由 Paul Mackerras 提交于 
      On 32-bit platforms, these convert from kernel virtual addresses
to real (physical addresses), like tophys/tovirt but they use
the same register for the source and destination.  On 64-bit
platforms, they do nothing because the hardware ignores the top
two bits of the address in real mode.

These new macros are used in fpu.S now.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      6316222e
  59. 26 10月, 2005 1 次提交
  61. 17 10月, 2005 1 次提交
  63. 13 10月, 2005 1 次提交
  65. 10 10月, 2005 1 次提交