[Patch 1/4] Allow arch-specific cleanup before breakpoint unregistration
From: Millton Miller <hidden>
Date: 2010-05-25 11:39:53
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lkml
Possibly related (same subject, not in this thread)
- 2010-05-24 · [Patch 1/4] Allow arch-specific cleanup before breakpoint unregistration · K.Prasad <hidden>
On Tue, 25 May 2010 at 14:43:56 +0530, K.Prasad wrote:
Certain architectures (such as PowerPC Book III S) have a need to cleanup data-structures before the breakpoint is unregistered. This patch introduces an arch-specific hook in release_bp_slot() along with a weak definition in the form of a stub funciton. Signed-off-by: K.Prasad <redacted> --- kernel/hw_breakpoint.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
My understanding is weak function definitions must appear in a different C file than their call sites to work on some toolchains. Andrew, can you confirm the above statement?
quoted hunk ↗ jump to hunk
Index: linux-2.6.ppc64_test/kernel/hw_breakpoint.c ===================================================================--- linux-2.6.ppc64_test.orig/kernel/hw_breakpoint.c +++ linux-2.6.ppc64_test/kernel/hw_breakpoint.c@@ -242,6 +242,17 @@ toggle_bp_slot(struct perf_event *bp, bo } /* + * Function to perform processor-specific cleanup during unregistration + */ +__weak void arch_unregister_hw_breakpoint(struct perf_event *bp) +{ + /* + * A weak stub function here for those archs that don't define + * it inside arch/.../kernel/hw_breakpoint.c + */ +} + +/* * Contraints to check before allowing this new breakpoint counter: * * == Non-pinned counter == (Considered as pinned for now)@@ -339,6 +350,7 @@ void release_bp_slot(struct perf_event * { mutex_lock(&nr_bp_mutex); + arch_unregister_hw_breakpoint(bp); __release_bp_slot(bp); mutex_unlock(&nr_bp_mutex);
Since the weak version is empty, should it just be delcared (in a header, put the comment there) and not defined? milton