On Mon, 2 Mar 2015, Stephane Eranian wrote:
> Vince, REGS_USER is user ONLY. It does not capture machine state if PMU
> interrupt occurred inside the kernel. REGS_USER is useful in support of dwarf
> based user level call stack unwinding. Otherwise REGS_INTR is what most
> analysis tools need.
so the summary is:
REGS_USER : gives you the registers at the time of interrupt,
but always in user mode (if in kernel reports
last ip before entered kernel)
useful for stack unwinding
REGS_INTR and precise_ip=0:
same as REGS_USER
REGS_INTR and precise_ip>0 and PEBS hardware:
gives you the register state at time
of interrupt. Can be inside of kernel.
do not enable REGS_USER and REG_INTR at the same time
as REGS_USER will have REG_INTR values and
cannot be used for user stack unwinding
Vince
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
