On Tue, Sep 30, 2014 at 08:39:38AM +0800, Chen Yucong wrote: > machine_check_poll() will scan all banks, so I think we can move it out > of the loop body.
Ok. > From: Chen Yucong > > machine_check_poll() will reset IA32_MCi_STATUS register to zero. > So we need to save the content of IA32_MCi_STATUS MSRs before > calling machine_check_poll() for logging threshold interrupt event. > > mce_setup() does not gather the content of IA32_MCG_STATUS, so it > should be read explicitly. And we also need to save MSR_IA32_MCx_ADDR > if MCI_STATUS_ADDRV bit field is valid. > > Signed-off-by: Chen Yucong <sla...@gmail.com> > --- > arch/x86/kernel/cpu/mcheck/mce_amd.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c > b/arch/x86/kernel/cpu/mcheck/mce_amd.c > index f8c56bd..f5a5beb 100644 > --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c > +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c > @@ -274,6 +274,7 @@ static void amd_threshold_interrupt(void) > struct mce m; > > mce_setup(&m); > + rdmsrl(MSR_IA32_MCG_STATUS, m.mcgstatus); > > /* assume first bank caused it */ > for (bank = 0; bank < mca_cfg.banks; ++bank) { > @@ -305,24 +306,28 @@ static void amd_threshold_interrupt(void) > (high & MASK_LOCKED_HI)) > continue; > > - /* > - * Log the machine check that caused the threshold > - * event. > - */ > - machine_check_poll(MCP_TIMESTAMP, > - this_cpu_ptr(&mce_poll_banks)); > - > if (high & MASK_OVERFLOW_HI) { > rdmsrl(address, m.misc); > rdmsrl(MSR_IA32_MCx_STATUS(bank), m.status); > + if (m.status & MCI_STATUS_ADDRV) > + rdmsrl(MSR_IA32_MCx_ADDR(bank), m.addr); > m.bank = K8_MCE_THRESHOLD_BASE > + bank * NR_BLOCKS > + block; > mce_log(&m); > - return; > + > + wrmsrl(MSR_IA32_MCx_STATUS(bank), 0); No, machine_check_poll will clear it anyway and now you're adding a purely useless MSR write here which costs. > + goto log_mcheck; Why goto? It will hit that machine_check_poll below even without it... > + > +log_mcheck: > + /* > + * Log the machine check that caused the threshold event. > + */ > + machine_check_poll(MCP_TIMESTAMP, > + this_cpu_ptr(&mce_poll_banks)); > } Of course, the more important question is: how are you testing your patches? Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- 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/