linux-toradex.git/include/linux/dynamic_debug.h, branch Colibri_T30_LinuxImageV2.1Beta2_20140206

jump label: Introduce static_branch() interface

2011-04-04T16:48:08+00:00

Introduce:

static __always_inline bool static_branch(struct jump_label_key *key);

instead of the old JUMP_LABEL(key, label) macro.

In this way, jump labels become really easy to use:

Define:

        struct jump_label_key jump_key;

Can be used as:

        if (static_branch(&jump_key))
                do unlikely code

enable/disale via:

        jump_label_inc(&jump_key);
        jump_label_dec(&jump_key);

that's it!

For the jump labels disabled case, the static_branch() becomes an
atomic_read(), and jump_label_inc()/dec() are simply atomic_inc(),
atomic_dec() operations. We show testing results for this change below.

Thanks to H. Peter Anvin for suggesting the 'static_branch()' construct.

Since we now require a 'struct jump_label_key *key', we can store a pointer into
the jump table addresses. In this way, we can enable/disable jump labels, in
basically constant time. This change allows us to completely remove the previous
hashtable scheme. Thanks to Peter Zijlstra for this re-write.

Testing:

I ran a series of 'tbench 20' runs 5 times (with reboots) for 3
configurations, where tracepoints were disabled.

jump label configured in
avg: 815.6

jump label *not* configured in (using atomic reads)
avg: 800.1

jump label *not* configured in (regular reads)
avg: 803.4

Signed-off-by: Peter Zijlstra 
LKML-Reference: <20110316212947.GA8792@redhat.com>
Signed-off-by: Jason Baron 
Suggested-by: H. Peter Anvin 
Tested-by: David Daney 
Acked-by: Ralf Baechle 
Acked-by: David S. Miller 
Acked-by: Mathieu Desnoyers 
Signed-off-by: Steven Rostedt

Dynamic debug: Add more flags

2011-02-03T23:39:16+00:00

Add flags that allow the user to specify via debugfs whether or not the
module name, function name, line number and/or thread ID have to be
included in the printed message.

Signed-off-by: Bart Van Assche 
Cc: Greg Banks 
Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Greg Kroah-Hartman

dynamic debug: Fix build issue with older gcc

2011-01-08T04:36:59+00:00

On older gcc (3.3) dynamic debug fails to compile:

include/net/inet_connection_sock.h: In function `inet_csk_reset_xmit_timer':
include/net/inet_connection_sock.h:236: error: duplicate label declaration `do_printk'
include/net/inet_connection_sock.h:219: error: this is a previous declaration
include/net/inet_connection_sock.h:236: error: duplicate label declaration `out'
include/net/inet_connection_sock.h:219: error: this is a previous declaration
include/net/inet_connection_sock.h:236: error: duplicate label `do_printk'
include/net/inet_connection_sock.h:236: error: duplicate label `out'

Fix, by reverting the usage of JUMP_LABEL() in dynamic debug for now.

Cc: 
Reported-by: Tetsuo Handa 
Tested-by: Tetsuo Handa 
Signed-off-by: Jason Baron 
Signed-off-by: Steven Rostedt

Merge branch 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block

2010-10-23T00:03:12+00:00

* 'for-2.6.37/drivers' of git://git.kernel.dk/linux-2.6-block: (95 commits)
  cciss: fix PCI IDs for new Smart Array controllers
  drbd: add race-breaker to drbd_go_diskless
  drbd: use dynamic_dev_dbg to optionally log uuid changes
  dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set
  drbd: cleanup: change "<= 0" to "== 0"
  drbd: relax the grace period of the md_sync timer again
  drbd: add some more explicit drbd_md_sync
  drbd: drop wrong debug asserts, fix recently introduced race
  drbd: cleanup useless leftover warn/error printk's
  drbd: add explicit drbd_md_sync to drbd_resync_finished
  drbd: Do not log an ASSERT for P_OV_REQUEST packets while C_CONNECTED
  drbd: fix for possible deadlock on IO error during resync
  drbd: fix unlikely access after free and list corruption
  drbd: fix for spurious fullsync (uuids rotated too fast)
  drbd: allow for explicit resync-finished notifications
  drbd: preparation commit, using full state in receive_state()
  drbd: drbd_send_ack_dp must not rely on header information
  drbd: Fix regression in recv_bm_rle_bits (compressed bitmap)
  drbd: Fixed a stupid copy and paste error
  drbd: Allow larger values for c-fill-target.
  ...

Fix up trivial conflict in drivers/block/ataflop.c due to BKL removal

dynamic_debug.h: Fix dynamic_dev_dbg() macro if CONFIG_DYNAMIC_DEBUG not set

2010-10-15T08:41:31+00:00

Signed-off-by: Philipp Reisner

jump label: Convert dynamic debug to use jump labels

2010-09-22T20:31:19+00:00

Convert the 'dynamic debug' infrastructure to use jump labels.

Signed-off-by: Jason Baron 
LKML-Reference: 
Signed-off-by: Steven Rostedt

module: initialize module dynamic debug later

2010-07-05T03:17:22+00:00

We should initialize the module dynamic debug datastructures
only after determining that the module is not loaded yet. This
fixes a bug that introduced in 2.6.35-rc2, where when a trying
to load a module twice, we also load it's dynamic printing data
twice which causes all sorts of nasty issues. Also handle
the dynamic debug cleanup later on failure.

Signed-off-by: Yehuda Sadeh 
Signed-off-by: Rusty Russell  (removed a #ifdef)
Signed-off-by: Linus Torvalds

DYNAMIC_DEBUG: fix documentation errors

2010-05-25T15:07:05+00:00

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Florian Ragwitz 
Cc: Jason Baron 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dynamic_debug.h/kernel.h: Remove KBUILD_MODNAME from dynamic_pr_debug

2009-12-15T16:53:25+00:00

If CONFIG_DYNAMIC_DEBUG is enabled and a source file has:

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include 

dynamic_debug.h will duplicate KBUILD_MODNAME
in the output string.

Remove the use of KBUILD_MODNAME from the
output format string generated by dynamic_debug.h

If CONFIG_DYNAMIC_DEBUG is not enabled, no compile-time
check is done to printk/dev_printk arguments.

Add it.

Signed-off-by: Joe Perches 
Cc: Jason Baron 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Driver core: remove pr_fmt() from dynamic_dev_dbg() printk

2009-04-16T23:17:11+00:00

When pr_fmt() was added to the pr_debug() code, we added it not only to the
dynamic_pr_debug() function, but also to the dynamic_dev_dbg() funciton.
However, dev_dbg() doesn't make use of pr_fmt(), so neither should
dynamic_dev_dbg().

Signed-off-by: Jason Baron 
Signed-off-by: Greg Kroah-Hartman