Messages in this thread | | | Date | Wed, 24 Nov 2010 14:18:04 -0500 | From | Jason Baron <> | Subject | Re: [PATCH 1/3] jump label: add enabled/disabled state to jump label key entries |
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On Wed, Nov 24, 2010 at 10:57:26AM -0500, Steven Rostedt wrote: > On Wed, 2010-11-24 at 10:21 -0500, Jason Baron wrote: > > > The keys are simply the address of a variable or structure (so as to be > > unique). We can put pointers or anything else in the variable. > > Note, there is not a 1 to 1 with keys and places that need to be > patched. > > Doing the following objdump: > > objdump -dr vmlinux | grep 'jmpq.*<trace_kmalloc' | wc -l > 375 > > That's 375 instances of kmalloc tracepoints[*] and one key. How do you > handle this? >
so there is 1 key associated with a kmalloc, call it key 'a'. Then, each time a trace_kmalloc is found in the text it generates a entry in the jump label section:
[to be patched address i] [address to jump to j] [key a] [to be patched address k] [address to jump to l] [key a] . .
So when we do jump_label_enable(key a), we patch all addresses associated with key a. Does this make sense?
> -- Steve > > > > > [*] this should be fixed, we probably should find a way to move the > tracepoint into the kmalloc functions that are not inlined. >
I believe there are patches pending for this.
thanks,
-Jason
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