Messages in this thread | | | Date | Mon, 25 Sep 2006 19:56:17 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [PATCH] Linux Kernel Markers 0.13 for 2.6.17 |
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Just as a precision :
The following sequence (please refer to the code below for local symbols 1 and 2) :
1: preempt_disable() call (*__mark_call_##name)(format, ## args); preempt_enable_no_resched() 2:
is insured because :
1 is part of an inline assembly with rw dependency on __marker_sequencer the call is surrounded by memory barriers. 2 is part of an inline assembly with rw dependency on __marker_sequencer
Mathieu
* Mathieu Desnoyers (compudj@krystal.dyndns.org) wrote: > +++ b/include/asm-generic/marker.h > @@ -0,0 +1,22 @@ > +/* > + * marker.h > + * > + * Code markup for dynamic and static tracing. Generic header. > + * > + * This file is released under the GPLv2. > + * See the file COPYING for more details. > + */ > + > +#define MARK_CALL(name, format, args...) \ > + do { \ > + static marker_probe_func *__mark_call_##name = \ > + __mark_empty_function; \ > + asm volatile( ".section .markers, \"a\";\n\t" \ > + ".long %1, %2;\n\t" \ > + ".previous;\n\t" : "+m" (__marker_sequencer) : \ > + "m" (__mark_call_##name), \ > + "m" (*format)); \ > + preempt_disable(); \ > + (*__mark_call_##name)(format, ## args); \ > + preempt_enable_no_resched(); \ > + } while(0)
> --- /dev/null > +++ b/include/asm-i386/marker.h > @@ -0,0 +1,30 @@ > +/* > + * marker.h > + * > + * Code markup for dynamic and static tracing. i386 architecture optimisations. > + * > + * (C) Copyright 2006 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> > + * > + * This file is released under the GPLv2. > + * See the file COPYING for more details. > + */ > + > +#include <asm-generic/marker.h> > + > +#define ARCH_HAS_MARK_JUMP > + > +/* Note : max 256 bytes between over_label and near_jump */ > +#define MARK_JUMP(name, format, args...) \ > + do { \ > + asm volatile( ".section .markers, \"a\";\n\t" \ > + ".long 0f, 1f, 2f;\n\t" \ > + ".previous;\n\t" \ > + ".align 16;\n\t" \ > + ".byte 0xeb;\n\t" \ > + "0:\n\t" \ > + ".byte 2f-1f;\n\t" \ > + "1:\n\t" \ > + : "+m" (__marker_sequencer) : ); \ > + MARK_CALL(name, format, ## args); \ > + asm volatile ( "2:\n\t" : "+m" (__marker_sequencer) : ); \ > + } while(0) OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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