02 Oct, 2010
1 commit
-
The kfifo_dma family of functions use sg_mark_end() on the last element in
their scatterlist. This forces use of a fresh scatterlist for each DMA
operation, which makes recycling a single scatterlist impossible.Change the behavior of the kfifo_dma functions to match the usage of the
dma_map_sg function. This means that users must respect the returned
nents value. The sample code is updated to reflect the change.This bug is trivial to cause: call kfifo_dma_in_prepare() such that it
prepares a scatterlist with a single entry comprising the whole fifo.
This is the case when you map the entirety of a newly created empty fifo.
This causes the setup_sgl() function to mark the first scatterlist entry
as the end of the chain, no matter what comes after it.Afterwards, add and remove some data from the fifo such that another call
to kfifo_dma_in_prepare() will create two scatterlist entries. It returns
nents=2. However, due to the previous sg_mark_end() call, sg_is_last()
will now return true for the first scatterlist element. This causes the
sample code to print a single scatterlist element when it should print
two.By removing the call to sg_mark_end(), we make the API as similar as
possible to the DMA mapping API. All users are required to respect the
returned nents.Signed-off-by: Ira W. Snyder
Cc: Stefani Seibold
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Aug, 2010
5 commits
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Provide a check in all the kfifo examples to validate the correct
execution of each testcase.Signed-off-by: Andrea Righi
Acked-by: Stefani Seibold
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We use a dynamically allocated kfifo in the dma example, so we need to
free it when unloading the module.Signed-off-by: Andrea Righi
Acked-by: Stefani Seibold
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The scatterlist is used uninitialized in kfifo_dma_in_prepare(). This
triggers the following bug if CONFIG_DEBUG_SG=y:------------[ cut here ]------------
kernel BUG at include/linux/scatterlist.h:65!
invalid opcode: 0000 [#1] PREEMPT SMP
...
Call Trace:
[] setup_sgl+0x6b/0xe0
[] ? example_init+0x0/0x265 [dma_example]
[] __kfifo_dma_in_prepare+0x21/0x30
[] example_init+0x124/0x265 [dma_example]
[] ? trace_module_notify+0x25/0x370
[] ? free_pages_prepare+0x11e/0x1e0
[] ? get_parent_ip+0x11/0x50
[] ? trace_module_notify+0x25/0x370
[] ? trace_hardirqs_on+0xd/0x10
[] ? mutex_unlock+0xe/0x10
[] ? trace_module_notify+0x41/0x370
[] ? __blocking_notifier_call_chain+0x45/0x80
[] ? vfree+0x2a/0x30
[] ? up_read+0x23/0x40
[] ? __blocking_notifier_call_chain+0x65/0x80
[] do_one_initcall+0x43/0x180
[] sys_init_module+0xba/0x200
[] system_call_fastpath+0x16/0x1b
RIP [] setup_sgl_buf+0x1a1/0x1b0
RSP
---[ end trace a72b979fd3c1d3a5 ]---Add the proper initialization to avoid the bug.
Signed-off-by: Andrea Righi
Acked-by: Stefani Seibold
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Provide a static array of expected items that kfifo should contain at the
end of the test to validate it.Signed-off-by: Andrea Righi
Cc: Stefani Seibold
Cc: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a testcase for kfifo_skip() to the byte stream fifo example.
Signed-off-by: Andrea Righi
Cc: Greg KH
Acked-by: Stefani Seibold
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Aug, 2010
1 commit
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Add four examples to the kernel sample directory.
It shows how to handle:
- a byte stream fifo
- a integer type fifo
- a dynamic record sized fifo
- the fifo DMA functions[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Stefani Seibold
Cc: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Aug, 2010
1 commit
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This KProbes example is a little useless if it doesn't print anything.
For MIPS print similar messages to those produced on x86 and PPC.Signed-off-by: David Daney
To: linux-mips@linux-mips.org
To: ananth@in.ibm.com
To: anil.s.keshavamurthy@intel.com
To: davem@davemloft.net
To: masami.hiramatsu.pt@hitachi.com
Cc: linux-kernel@vger.kernel.org
Cc: hschauhan@nulltrace.org
Patchwork: https://patchwork.linux-mips.org/patch/1528/
Signed-off-by: Ralf Baechle
14 May, 2010
1 commit
-
This patch adds data to be passed to tracepoint callbacks.
The created functions from DECLARE_TRACE() now need a mandatory data
parameter. For example:DECLARE_TRACE(mytracepoint, int value, value)
Will create the register function:
int register_trace_mytracepoint((void(*)(void *data, int value))probe,
void *data);As the first argument, all callbacks (probes) must take a (void *data)
parameter. So a callback for the above tracepoint will look like:void myprobe(void *data, int value)
{
}The callback may choose to ignore the data parameter.
This change allows callbacks to register a private data pointer along
with the function probe.void mycallback(void *data, int value);
register_trace_mytracepoint(mycallback, mydata);
Then the mycallback() will receive the "mydata" as the first parameter
before the args.A more detailed example:
DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));
/* In the C file */
DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));
[...]
trace_mytracepoint(status);
/* In a file registering this tracepoint */
int my_callback(void *data, int status)
{
struct my_struct my_data = data;
[...]
}[...]
my_data = kmalloc(sizeof(*my_data), GFP_KERNEL);
init_my_data(my_data);
register_trace_mytracepoint(my_callback, my_data);The same callback can also be registered to the same tracepoint as long
as the data registered is different. Note, the data must also be used
to unregister the callback:unregister_trace_mytracepoint(my_callback, my_data);
Because of the data parameter, tracepoints declared this way can not have
no args. That is:DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS());
will cause an error.
If no arguments are needed, a new macro can be used instead:
DECLARE_TRACE_NOARGS(mytracepoint);
Since there are no arguments, the proto and args fields are left out.
This is part of a series to make the tracepoint footprint smaller:
text data bss dec hex filename
4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
4914025 1088868 861512 6864405 68be15 vmlinux.class
4918492 1084612 861512 6864616 68bee8 vmlinux.tracepointAgain, this patch also increases the size of the kernel, but
lays the ground work for decreasing it.v5: Fixed net/core/drop_monitor.c to handle these updates.
v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the
#ifdef CONFIG_TRACE_POINTS, since the two are the same in both
cases. The __DECLARE_TRACE() is what changes.
Thanks to Frederic Weisbecker for pointing this out.v3: Made all register_* functions require data to be passed and
all callbacks to take a void * parameter as its first argument.
This makes the calling functions comply with C standards.Also added more comments to the modifications of DECLARE_TRACE().
v2: Made the DECLARE_TRACE() have the ability to pass arguments
and added a new DECLARE_TRACE_NOARGS() for tracepoints that
do not need any arguments.Acked-by: Mathieu Desnoyers
Acked-by: Masami Hiramatsu
Acked-by: Frederic Weisbecker
Cc: Neil Horman
Cc: David S. Miller
Signed-off-by: Steven Rostedt
30 Mar, 2010
1 commit
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…it 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 allmodconfig8. 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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
10 Mar, 2010
1 commit
-
Conflicts:
tools/perf/util/probe-event.cMerge reason: Pick up -rc1 and resolve the conflict as well.
Signed-off-by: Ingo Molnar
08 Mar, 2010
3 commits
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Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime* potentially better optimized code as the compiler
can assume that the const data cannot be changed* the compiler/linker move const data into .rodata
and therefore exclude them from false sharingSigned-off-by: Emese Revfy
Acked-by: David Teigland
Acked-by: Matt Domsch
Acked-by: Maciej Sosnowski
Acked-by: Hans J. Koch
Acked-by: Pekka Enberg
Acked-by: Jens Axboe
Acked-by: Stephen Hemminger
Signed-off-by: Greg Kroah-Hartman -
No change in functionality.
Signed-off-by: Radu Voicilas
Signed-off-by: Greg Kroah-Hartman -
No change in functionality.
Signed-off-by: Radu Voicilas
Signed-off-by: Greg Kroah-Hartman
27 Feb, 2010
1 commit
-
Add __percpu sparse annotations to hw_breakpoint.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.In kernel/hw_breakpoint.c, per_cpu(nr_task_bp_pinned, cpu)'s will
trigger spurious noderef related warnings from sparse. Changing it to
&per_cpu(nr_task_bp_pinned[0], cpu) will work around the problem but
deemed to ugly by the maintainer. Leave it alone until better
solution can be found.Signed-off-by: Tejun Heo
Cc: Stephen Rothwell
Cc: K.Prasad
LKML-Reference:
Signed-off-by: Frederic Weisbecker
12 Dec, 2009
1 commit
-
…/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (57 commits)
x86, perf events: Check if we have APIC enabled
perf_event: Fix variable initialization in other codepaths
perf kmem: Fix unused argument build warning
perf symbols: perf_header__read_build_ids() offset'n'size should be u64
perf symbols: dsos__read_build_ids() should read both user and kernel buildids
perf tools: Align long options which have no short forms
perf kmem: Show usage if no option is specified
sched: Mark sched_clock() as notrace
perf sched: Add max delay time snapshot
perf tools: Correct size given to memset
perf_event: Fix perf_swevent_hrtimer() variable initialization
perf sched: Fix for getting task's execution time
tracing/kprobes: Fix field creation's bad error handling
perf_event: Cleanup for cpu_clock_perf_event_update()
perf_event: Allocate children's perf_event_ctxp at the right time
perf_event: Clean up __perf_event_init_context()
hw-breakpoints: Modify breakpoints without unregistering them
perf probe: Update perf-probe document
perf probe: Support --del option
trace-kprobe: Support delete probe syntax
...
08 Dec, 2009
1 commit
-
Conflicts:
kernel/irq/chip.c
06 Dec, 2009
1 commit
-
struct perf_event::event callback was called when a breakpoint
triggers. But this is a rather opaque callback, pretty
tied-only to the breakpoint API and not really integrated into perf
as it triggers even when we don't overflow.We prefer to use overflow_handler() as it fits into the perf events
rules, being called only when we overflow.Reported-by: Peter Zijlstra
Signed-off-by: Frederic Weisbecker
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: "K. Prasad"
27 Nov, 2009
1 commit
-
Kernel breakpoints are created using functions in which we pass
breakpoint parameters as individual variables: address, length
and type.Although it fits well for x86, this just does not scale across
architectures that may support this api later as these may have
more or different needs. Pass in a perf_event_attr structure
instead because it is meant to evolve as much as possible into
a generic hardware breakpoint parameter structure.Reported-by: K.Prasad
Signed-off-by: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar
26 Nov, 2009
1 commit
-
This simplifies the error handling when we create a breakpoint.
We don't need to check the NULL return value corner case anymore
since we have improved perf_event_create_kernel_counter() to
always return an error code in the failure case.Signed-off-by: Frederic Weisbecker
Cc: Peter Zijlstra
Cc: Arnaldo Carvalho de Melo
Cc: Paul Mackerras
Cc: Steven Rostedt
Cc: Prasad
LKML-Reference:
Signed-off-by: Ingo Molnar
24 Nov, 2009
1 commit
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Attribute authorship to developers of hw-breakpoint related
files.Signed-off-by: K.Prasad
Cc: Alan Stern
Cc: Frederic Weisbecker
LKML-Reference:
[ v2: moved it to latest -tip ]
Signed-off-by: Ingo Molnar
10 Nov, 2009
1 commit
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The hw-breakpoint sample module has been broken during the
hw-breakpoint internals refactoring. Propagate the changes
to it.Reported-by: "K. Prasad"
Signed-off-by: Frederic Weisbecker
09 Nov, 2009
1 commit
-
Additionally, some excessive newlines removed.
Signed-off-by: Michael Roth
Signed-off-by: Jiri Kosina
18 Oct, 2009
1 commit
-
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/MakefileMerge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
02 Oct, 2009
1 commit
-
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Sep, 2009
1 commit
-
Now that the last users of markers have migrated to the event
tracer we can kill off the (now orphan) support code.Signed-off-by: Christoph Hellwig
Acked-by: Mathieu Desnoyers
Cc: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar
16 Sep, 2009
1 commit
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Default directory of debug filesystem for ftrace is /sys/kernel/debug/.
Signed-off-by: GeunSik Lim
Signed-off-by: Greg Kroah-Hartman
15 Sep, 2009
1 commit
-
Conflicts:
arch/x86/kernel/process_64.cSemantic conflict fixed in:
arch/x86/kvm/x86.cSigned-off-by: Ingo Molnar
07 Sep, 2009
1 commit
-
Conflicts:
arch/Kconfig
kernel/trace/trace.hMerge reason: resolve the conflicts, plus adopt to the new
ring-buffer APIs.Signed-off-by: Ingo Molnar
17 Aug, 2009
1 commit
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sched.h inclusion is definitely not needed like in 32-bit version,
remove it, fixup compilation.Signed-off-by: Alexey Dobriyan
Signed-off-by: David S. Miller
13 Jul, 2009
1 commit
-
If TRACE_INCLDUE_FILE is defined,
will be included and compiled, otherwise it will beSo TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.Imaging this scenario:
#include
-> TRACE_SYSTEM == foo
...
#include
-> TRACE_SYSTEM == bar
...
#define CREATE_TRACE_POINTS
#include
-> TRACE_SYSTEM == bar !!!and then bar.h will be included and compiled.
Signed-off-by: Li Zefan
Cc: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar
21 Jun, 2009
1 commit
-
…nel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
tracing/urgent: warn in case of ftrace_start_up inbalance
tracing/urgent: fix unbalanced ftrace_start_up
function-graph: add stack frame test
function-graph: disable when both x86_32 and optimize for size are configured
ring-buffer: have benchmark test print to trace buffer
ring-buffer: do not grab locks in nmi
ring-buffer: add locks around rb_per_cpu_empty
ring-buffer: check for less than two in size allocation
ring-buffer: remove useless compile check for buffer_page size
ring-buffer: remove useless warn on check
ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
tracing: update sample event documentation
tracing/filters: fix race between filter setting and module unload
tracing/filters: free filter_string in destroy_preds()
ring-buffer: use commit counters for commit pointer accounting
ring-buffer: remove unused variable
ring-buffer: have benchmark test handle discarded events
ring-buffer: prevent adding write in discarded area
tracing/filters: strloc should be unsigned short
tracing/filters: operand can be negative
...Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
17 Jun, 2009
2 commits
-
Conflicts:
arch/x86/Kconfig
arch/x86/kernel/traps.c
arch/x86/power/cpu.c
arch/x86/power/cpu_32.c
kernel/MakefileSemantic conflict:
arch/x86/kernel/hw_breakpoint.cMerge reason: Resolve the conflicts, move from put_cpu_no_sched() to
put_cpu() in arch/x86/kernel/hw_breakpoint.c.Signed-off-by: Ingo Molnar
-
The comments in the sample code is a bit confusing. This patch
cleans them up a little.Signed-off-by: Steven Rostedt
16 Jun, 2009
2 commits
-
The firmware example files are beyond broken, and will not work, and
should not be used as an example at all. So lets remove them and hope
someone writes new files sometime in the future.Signed-off-by: Greg Kroah-Hartman
-
With SAMPLE_KOBJECT=y, it isn't even linked into the kernel image.
Signed-off-by: Michal Marek
Signed-off-by: Greg Kroah-Hartman
03 Jun, 2009
1 commit
-
This patch introduces a sample kernel module to demonstrate the use of Hardware
Breakpoint feature. It places a breakpoint over the kernel variable 'pid_max'
to monitor all write operations and emits a function-backtrace when done.Signed-off-by: K.Prasad
Signed-off-by: Frederic Weisbecker
07 May, 2009
1 commit
-
When creating trace events for ftrace, the header file with the TRACE_EVENT
macros must also have a macro called TRACE_SYSTEM. This macro describes
the name of the system the TRACE_EVENTS are defined for. It also doubles
as a way for the define_trace.h file to include the file that included
it.For example:
in irq.h
#define TRACE_SYSTEM irq
[...]
#include
The define_trace will use TRACE_SYSTEM to include irq.h. But if the name
of the trace system does not match the name of the trace header file,
one can override it with:Which will change define_trace.h to inclued foo_trace.h instead of foo.h
The sample comments this, but people that use the sample code will more
likely use the code and not read the comments. This patch changes the
sample code to use the TRACE_INCLUDE_FILE to better show developers how to
use it.[ Impact: make sample less confusing to developers ]
Reported-by: Christoph Hellwig
Signed-off-by: Steven Rostedt
06 May, 2009
2 commits
-
Use -I$(src) to add the current directory the include path.
[ Impact: cleanup ]
Signed-off-by: Christoph Hellwig
Acked-by: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
Normally a config should be default to n. This patch also makes the
sample module-only, like SAMPLE_MARKERS and SAMPLE_TRACEPOINTS.[ Impact: don't build trace event sample by default ]
Signed-off-by: Li Zefan
Acked-by: Steven Rostedt
Acked-by: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar