On 09/09/2013 02:55 PM, Seiji Aguchi wrote:
> Change from v2
> - Print entry->ip instead of entry->regs->ip to avoid kernel crash.
> - Use %pf instead of 0x%lx to print address and ip.
>
> This patch introduces page fault tracepoints to x86 architecture
> by switching IDT.
>
> [Use case of page fault events]
>
> Two events, for user and kernel spaces, are introduced at the beginning of
> page fault handler.
>
> - User space event
> There is a request of page fault event for user space as below.
>
> http://marc.info/?l=linux-mm&m=136807959830182&w=2
> http://marc.info/?l=linux-mm&m=136807959130175&w=2
>
For permanence, please use links of the form:
http://lkml.kernel.org/r/message-id
(Yes, they currently point to marc.info, but can be redirected to point
to any archive.)
> - Kernel space event:
> Overhead in kernel space is measurable by enabling it.
>
> [Creating IDT]
>
> A way to create IDT is as below.
>
> - Introduce set_intr_gate_raw() to register just non-trace handler to IDT.
> This is used at boot time which tracing is disabled.
> - Make set_intr_gate() macro so that it can register trace handler to
> trace IDT and non-trace handler to normal IDT.
>
This is needlessly confusing, which is apart of why reviewing this patch
took a lot more time than it should.
Please break this patch into two: one which sets up the tracing IDT and
one to create the #PF tracepoint. The assumption is, I am assuming,
there will be more.
-hpa
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