Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
大约 1 年 前同步成功

通知 158
Star 36
Fork 7
cloud-kernel
cloud-kernel

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 03 2月, 2011 1 次提交
    • S
      tracing: Replace trace_event struct array with pointer array · e4a9ea5e
      由 Steven Rostedt 提交于 
      Currently the trace_event structures are placed in the _ftrace_events
section, and at link time, the linker makes one large array of all
the trace_event structures. On boot up, this array is read (much like
the initcall sections) and the events are processed.

The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.

A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).

Instead of packing the structures into an array, the structures' addresses
are now put into the _ftrace_event section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).

By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.

The _ftrace_event section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: NDavid Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      e4a9ea5e
  3. 20 1月, 2011 1 次提交
    • T
      lockdep: Move early boot local IRQ enable/disable status to init/main.c · 2ce802f6
      由 Tejun Heo 提交于 
      During early boot, local IRQ is disabled until IRQ subsystem is
properly initialized.  During this time, no one should enable
local IRQ and some operations which usually are not allowed with
IRQ disabled, e.g. operations which might sleep or require
communications with other processors, are allowed.

lockdep tracked this with early_boot_irqs_off/on() callbacks.
As other subsystems need this information too, move it to
init/main.c and make it generally available.  While at it,
toggle the boolean to early_boot_irqs_disabled instead of
enabled so that it can be initialized with %false and %true
indicates the exceptional condition.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NPekka Enberg <penberg@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110120110635.GB6036@htj.dyndns.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2ce802f6
  5. 15 1月, 2011 1 次提交
    • L
      tracing: Remove syscall_exit_fields · 7f85803a
      由 Lai Jiangshan 提交于 
      There is no need for syscall_exit_fields as the syscall
exit event class can already host the fields in its structure,
like most other trace events do by default. Use that
default behavior instead.

Following this scheme, we don't need anymore to override the
get_fields() callback of the syscall exit event class either.

Hence both syscall_exit_fields and syscall_get_exit_fields() can
be removed.

Also changed some indentation to keep the following under 80
characters:

".fields		= LIST_HEAD_INIT(event_class_syscall_exit.fields),"
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <4D301C0E.8090408@cn.fujitsu.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      7f85803a
  7. 10 1月, 2011 1 次提交
  9. 08 1月, 2011 2 次提交
  11. 07 1月, 2011 2 次提交
  13. 04 1月, 2011 2 次提交
  15. 24 12月, 2010 1 次提交
    • D
      ring_buffer: Off-by-one and duplicate events in ring_buffer_read_page · e1e35927
      由 David Sharp 提交于 
      Fix two related problems in the event-copying loop of
ring_buffer_read_page.

The loop condition for copying events is off-by-one.
"len" is the remaining space in the caller-supplied page.
"size" is the size of the next event (or two events).
If len == size, then there is just enough space for the next event.

size was set to rb_event_ts_length, which may include the size of two
events if the first event is a time-extend, in order to assure time-
extends are kept together with the event after it. However,
rb_advance_reader always advances by one event. This would result in the
event after any time-extend being duplicated. Instead, get the size of
a single event for the memcpy, but use rb_event_ts_length for the loop
condition.
Signed-off-by: NDavid Sharp <dhsharp@google.com>
LKML-Reference: <1293064704-8101-1-git-send-email-dhsharp@google.com>
LKML-Reference: <AANLkTin7nLrRPc9qGjdjHbeVDDWiJjAiYyb-L=gH85bx@mail.gmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      e1e35927
  17. 01 12月, 2010 1 次提交
  19. 19 11月, 2010 1 次提交
    • S
      tracing/events: Show real number in array fields · 04295780
      由 Steven Rostedt 提交于 
      Currently we have in something like the sched_switch event:

  field:char prev_comm[TASK_COMM_LEN];	offset:12;	size:16;	signed:1;

When a userspace tool such as perf tries to parse this, the
TASK_COMM_LEN is meaningless. This is done because the TRACE_EVENT() macro
simply uses a #len to show the string of the length. When the length is
an enum, we get a string that means nothing for tools.

By adding a static buffer and a mutex to protect it, we can store the
string into that buffer with snprintf and show the actual number.
Now we get:

  field:char prev_comm[16];       offset:12;      size:16;        signed:1;

Something much more useful.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      04295780
  21. 18 11月, 2010 2 次提交
  23. 16 11月, 2010 1 次提交
  25. 13 11月, 2010 1 次提交
    • S
      tracing: Fix recursive user stack trace · 91e86e56
      由 Steven Rostedt 提交于 
      The user stack trace can fault when examining the trace. Which
would call the do_page_fault handler, which would trace again,
which would do the user stack trace, which would fault and call
do_page_fault again ...

Thus this is causing a recursive bug. We need to have a recursion
detector here.

[ Resubmitted by Jiri Olsa ]

[ Eric Dumazet recommended using __this_cpu_* instead of __get_cpu_* ]

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
LKML-Reference: <1289390172-9730-3-git-send-email-jolsa@redhat.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      91e86e56
  27. 10 11月, 2010 2 次提交
    • C
      block: remove REQ_HARDBARRIER · 02e031cb
      由 Christoph Hellwig 提交于 
      REQ_HARDBARRIER is dead now, so remove the leftovers.  What's left
at this point is:

 - various checks inside the block layer.
 - sanity checks in bio based drivers.
 - now unused bio_empty_barrier helper.
 - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
   but Xen really needs to sort out it's barrier situaton.
 - setting of ordered tags in uas - dead code copied from old scsi
   drivers.
 - scsi different retry for barriers - it's dead and should have been
   removed when flushes were converted to FS requests.
 - blktrace handling of barriers - removed.  Someone who knows blktrace
   better should add support for REQ_FLUSH and REQ_FUA, though.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
      02e031cb
    • H
      [S390] ftrace: build without frame pointers on s390 · becf91f1
      由 Heiko Carstens 提交于 
      s390 doesn't need FRAME_POINTERS in order to have a working function tracer.
We don't need frame pointers in order to get strack traces since we always
have valid backchains by using the -mkernel-backchain gcc option.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      becf91f1
  29. 02 11月, 2010 1 次提交
  31. 28 10月, 2010 1 次提交
  33. 24 10月, 2010 1 次提交
  35. 23 10月, 2010 2 次提交
  37. 21 10月, 2010 6 次提交
    • S
      tracing: Do not limit the size of the number of CPU buffers · dd49a38c
      由 Steven Rostedt 提交于 
      The tracing per_cpu buffers were limited to 999 CPUs for a mear
savings in stack space of a char array. Up the array to 30 characters
which is more than enough to hold a 64 bit number.
Reported-by: NRobin Holt <holt@sgi.com>
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      dd49a38c
    • S
      ring-buffer: Remove unused macro RB_TIMESTAMPS_PER_PAGE · b8b2663b
      由 Steven Rostedt 提交于 
      With the binding of time extends to events we no longer need to use
the macro RB_TIMESTAMPS_PER_PAGE. Remove it.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      b8b2663b
    • S
      ring-buffer: Micro-optimize with some strategic inlining · d9abde21
      由 Steven Rostedt 提交于 
      By using inline and noinline, we are able to make the fast path of
recording an event 4% faster.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      d9abde21
    • S
      ring-buffer: Remove condition to add timestamp in fast path · 140ff891
      由 Steven Rostedt 提交于 
      There's a condition to check if we should add a time extend or
not in the fast path. But this condition is racey (in the sense
that we can add a unnecessary time extend, but nothing that
can break anything). We later check if the time or event time
delta should be zero or have real data in it (not racey), making
this first check redundant.

This check may help save space once in a while, but really is
not worth the hassle to try to save some space that happens at
most 134 ms at a time.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      140ff891
    • S
      ring-buffer: Bind time extend and data events together · 69d1b839
      由 Steven Rostedt 提交于 
      When the time between two timestamps is greater than
2^27 nanosecs (~134 ms) a time extend event is added that extends
the time difference to 59 bits (~18 years). This is due to
events only having a 27 bit field to store time.

Currently this time extend is a separate event. We add it just before
the event data that is being written to the buffer. But before
the event data is committed, the event data can also be discarded (as
with the case of filters). But because the time extend has already been
committed, it will stay in the buffer.

If lots of events are being filtered and no event is being
written, then every 134ms a time extend can be added to the buffer
without any data attached. To keep from filling the entire buffer
with time extends, a time extend will never be the first event
in a page because the page timestamp can be used. Time extends can
only fill the rest of a page with some data at the beginning.

This patch binds the time extend with the data. The difference here
is that the time extend is not committed before the data is added.
Instead, when a time extend is needed, the space reserved on
the ring buffer is the time extend + the data event size. The
time extend is added to the first part of the reserved block and
the data is added to the second. The time extend event is passed
back to the reserver, but since the reserver also uses a function
to find the data portion of the reserved block, no changes to the
ring buffer interface need to be made.

When a commit is discarded, we now remove both the time extend and
the event. With this approach no more than one time extend can
be in the buffer in a row. Data must always follow a time extend.

Thanks to Mathieu Desnoyers for suggesting this idea.
Suggested-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      69d1b839
    • S
      ring-buffer: Pass delta by value and not by reference · f25106ae
      由 Steven Rostedt 提交于 
      The delta between events is passed to the timestamp code by reference
and the timestamp code will reset the value. But it can be reset
from the caller. No need to pass it in by reference.

By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the delta in a register and not
worry about updating the reference.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      f25106ae
  39. 20 10月, 2010 2 次提交
    • S
      ring-buffer: Pass timestamp by value and not by reference · e8bc43e8
      由 Steven Rostedt 提交于 
      The original code for the ring buffer had locations that modified
the timestamp and that change was used by the callers. Now,
the timestamp is not reused by the callers and there is no reason
to pass it by reference.

By changing the call to pass by value, lets gcc optimize the code
a bit more where it can store the timestamp in a register and not
worry about updating the reference.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      e8bc43e8
    • S
      ring-buffer: Make write slow path out of line · 747e94ae
      由 Steven Rostedt 提交于 
      Gcc inlines the slow path of the ring buffer write which can
hurt performance. This patch simply forces the slow path function
rb_move_tail() to always be a function.

The ring_buffer_benchmark module with reader_disabled=1 shows that
this patch changes the time to record an event from 135 ns to
132 ns. (3 ns or 2.22% improvement)
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      747e94ae
  41. 19 10月, 2010 2 次提交
  43. 18 10月, 2010 6 次提交