Messages in this thread | | | Subject | Re: [patch 02/11] x86 architecture implementation of Hardware Breakpoint interfaces | From | Benjamin Herrenschmidt <> | Date | Sat, 14 Mar 2009 14:47:35 +1100 |
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On Wed, 2009-03-11 at 23:11 +0530, K.Prasad wrote: > With FCFS or an allocation mechanism without the (un)installed() > callbacks we'd lose the ability to record requests and service them > later when registers become availabile. > > Say when (un)installed() callbacks are implemented for the proposed > ftrace-plugin to trace kernel symbols, they can automatically stop/start > tracing as and when registers become (un)available. This can be helpful when > we wish to profile memory access over a kernel variable for a long duration > (where small loss of tracing data can be tolerated), while the system would > permit simultaneous user-space access (say a GDB session using 'hbreak'). > > Are we fine with disallowing such usage, which if done will let the requester > of the breakpoint register 'poll' periodically to check availability.
Is that such a big deal ? Can't we just have the kernel degrade to classic SW breakpoints ?
Smells like overengineering to me ...
Ben.
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