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Message-ID: <4488E275.1020304@intel.com>
Date: Fri, 09 Jun 2006 03:03:00 -0000
From: "bibo,mao" <bibo.mao@intel.com>
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To: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp>
CC: "Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>,   Ananth N Mavinakayanahalli <ananth@in.ibm.com>,  SystemTAP <systemtap@sources.redhat.com>,   Yumiko Sugita <sugita@sdl.hitachi.co.jp>,  Satoshi Oshima <soshima@redhat.com>, Hideo Aoki <haoki@redhat.com>,   Prasanna S Panchamukhi <prasanna@in.ibm.com>,  Jim Keniston <jkenisto@us.ibm.com>
Subject: Re: [PATCH]kprobe booster for IA64
References: <4485223C.8090109@sdl.hitachi.co.jp> <44868B03.70108@intel.com> <448834B6.1010002@sdl.hitachi.co.jp>
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Masami Hiramatsu wrote:
> Hi bibo,
> 
> bibo,mao wrote:
>  > hiramatu san,
>  > If the probed instruction can cause one fault, there may be some problem.
>  > Because original instruction is copied into 2nd element of ainsn.insn,
>  > instruction execution address is different, search_exception_tables result
>  > will be different also.
> 
> Thank you for your good advice.
> As far as I can see, the search_exception_tables() checks whether the
> page-fault address is expected to cause an exception.
> If it is correct, I think the problem can be avoided by disabling
> booster if the table contains the target address.
> For example;
> 
>         if (can_boost(template) && !search_exception_tables(p->addr)) {
>                 p->ainsn.inst_flag |= INST_FLAG_BOOSTABLE;
>         }
> 
> What would you think about this idea?
> 
> Thanks
> 
That's good for me. BTW in IA64 one bundle has three instructions, I think
that this bundle should be judged whether it is within exception table.

Thanks
bibo,mao