History log of /lib/ratelimit.c
Revision Date Author Comments
8bc3bcc93a2b4e47d5d410146f6546bca6171663 17-Nov-2011 Paul Gortmaker <paul.gortmaker@windriver.com> lib: reduce the use of module.h wherever possible

For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
07354eb1a74d1e1ece29f8bafe0b46e8c77a95ef 25-Jul-2009 Thomas Gleixner <tglx@linutronix.de> locking, printk: Annotate logbuf_lock as raw

The logbuf_lock lock can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[ merged and fixed it ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
57119c34e53bbb8d244c3ff1335ef5145768538f 06-Apr-2010 Yong Zhang <yong.zhang@windriver.com> ratelimit: fix the return value when __ratelimit() fails to acquire the lock

The log of commit edaac8e3167501cda336231d00611bf59c164346 ("ratelimit:
Fix/allow use in atomic contexts"), indicates that we want to suppress the
callback when the trylock fails.

Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2a7268abc48c8009b284bd88605d14fcb65772ec 06-Apr-2010 Yong Zhang <yong.zhang@windriver.com> ratelimit: annotate ___ratelimit()

To prevent from wrongly using the return value.

[akpm@linux-foundation.org: fix spello]
Signed-off-by: Yong Zhang <yong.zhang@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5c828713358cb9df8aa174371edcbbb62203a490 23-Oct-2009 Christian Borntraeger <borntraeger@de.ibm.com> ratelimit: Make suppressed output messages more useful

Today I got:

[39648.224782] Registered led device: iwl-phy0::TX
[40676.545099] __ratelimit: 246 callbacks suppressed
[40676.545103] abcdef[23675]: segfault at 0 ...

as you can see the ratelimit message contains a function prefix.
Since this is always __ratelimit, this wont help much.

This patch changes __ratelimit and printk_ratelimit to print the
function name that calls ratelimit.

This will pinpoint the responsible function, as long as not several
different places call ratelimit with the same ratelimit state at
the same time. In that case we catch only one random function that
calls ratelimit after the wait period.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
CC: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <200910231458.11832.borntraeger@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
3fff4c42bd0a89869a0eb1e7874cc06ffa4aa0f5 22-Sep-2009 Ingo Molnar <mingo@elte.hu> printk: Remove ratelimit.h from kernel.h

Decouple kernel.h from ratelimit.h: the global declaration of
printk's ratelimit_state is not needed, and it leads to messy
circular dependencies due to ratelimit.h's (new) adding of a
spinlock_types.h include.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
edaac8e3167501cda336231d00611bf59c164346 22-Sep-2009 Ingo Molnar <mingo@elte.hu> ratelimit: Fix/allow use in atomic contexts

I'd like to use printk_ratelimit() in NMI context, but it's not
robust right now due to spinlock usage in lib/ratelimit.c. If an
NMI is unlucky enough to hit just that spot we might lock up trying
to take the spinlock again.

Fix that by using a trylock variant. If we contend on that lock we
can genuinely skip the message because the state is just being
accessed by another CPU (or by this CPU).

( We could use atomics for the suppressed messages field, but
i doubt it matters in practice and it makes the code heavier. )

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
979f693def9084a452846365dfde5dcb28366333 22-Sep-2009 Ingo Molnar <mingo@elte.hu> ratelimit: Use per ratelimit context locking

I'd like to use printk_ratelimit() in atomic context, but that's
not possible right now due to the spinlock usage this commit
introduced more than a year ago:

717115e: printk ratelimiting rewrite

As a first step push the lock into the ratelimit state structure.
This allows us to deal with locking failures to be considered as an
event related to that state being too busy.

Also clean up the code a bit (without changing functionality):

- tidy up the definitions

- clean up the code flow

This also shrinks the code a tiny bit:

text data bss dec hex filename
264 0 4 268 10c ratelimit.o.before
255 0 0 255 ff ratelimit.o.after

( Whole-kernel data size got a bit larger, because we have
two ratelimit-state data structures right now. )

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
4d9c377c81d37740b25cacf025f95c084eafabbb 29-Jul-2008 Alexey Dobriyan <adobriyan@gmail.com> __ratelimit() cpu flags can't be static

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
717115e1a5856b57af0f71e1df7149108294fc10 25-Jul-2008 Dave Young <hidave.darkstar@gmail.com> printk ratelimiting rewrite

All ratelimit user use same jiffies and burst params, so some messages
(callbacks) will be lost.

For example:
a call printk_ratelimit(5 * HZ, 1)
b call printk_ratelimit(5 * HZ, 1) before the 5*HZ timeout of a, then b will
will be supressed.

- rewrite __ratelimit, and use a ratelimit_state as parameter. Thanks for
hints from andrew.

- Add WARN_ON_RATELIMIT, update rcupreempt.h

- remove __printk_ratelimit

- use __ratelimit in net_ratelimit

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
5f97a5a8799b8d7d0afdb9d68a50a4e0e8298a05 29-Apr-2008 Dave Young <hidave.darkstar@gmail.com> isolate ratelimit from printk.c for other use

Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some
serious complaining of kernel, we need repeat the warnings, so here I isolate
the ratelimit part of printk.c to a standalone file.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>