| Message ID | 20170406045537.1573-1-haozhong.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
>>> On 06.04.17 at 06:55, <haozhong.zhang@intel.com> wrote: > 1. Move them into mcheck_cmn_handler() which is their only user. This part is uncontroversial. > 2. Always (re-)initialize them to clear historical information. But without further explanation I'm not convinced this part is correct. That's a good indication that you should split patches. I assume, btw, that you're aware that these patches won't go in very soon (not until after 4.9 has been branched off), unless they fix an actual bug. Jan
On 04/06/17 01:54 -0600, Jan Beulich wrote: > >>> On 06.04.17 at 06:55, <haozhong.zhang@intel.com> wrote: > > 1. Move them into mcheck_cmn_handler() which is their only user. > > This part is uncontroversial. > > > 2. Always (re-)initialize them to clear historical information. > > But without further explanation I'm not convinced this part is correct. > That's a good indication that you should split patches. > > I assume, btw, that you're aware that these patches won't go > in very soon (not until after 4.9 has been branched off), unless > they fix an actual bug. > Please drop this patch as it does not fix any bug. I was blind. 'found_error' is already cleared after mcheck_cmn_handler() used it. Non-empty 'mce_fatal_errors' results in mc_panic(), so there is no need to clear it. Sorry for the noise. Haozhong
>>> On 06.04.17 at 10:49, <haozhong.zhang@intel.com> wrote: > On 04/06/17 01:54 -0600, Jan Beulich wrote: >> >>> On 06.04.17 at 06:55, <haozhong.zhang@intel.com> wrote: >> > 1. Move them into mcheck_cmn_handler() which is their only user. >> >> This part is uncontroversial. >> >> > 2. Always (re-)initialize them to clear historical information. >> >> But without further explanation I'm not convinced this part is correct. >> That's a good indication that you should split patches. >> >> I assume, btw, that you're aware that these patches won't go >> in very soon (not until after 4.9 has been branched off), unless >> they fix an actual bug. >> > > Please drop this patch as it does not fix any bug. I was blind. > 'found_error' is already cleared after mcheck_cmn_handler() used it. > Non-empty 'mce_fatal_errors' results in mc_panic(), so there is no > need to clear it. > > Sorry for the noise. Well, reducing the scope of the variables is still a worthwhile thing. Jan
diff --git a/xen/arch/x86/cpu/mcheck/mce.c b/xen/arch/x86/cpu/mcheck/mce.c index 11d0e23..7618120 100644 --- a/xen/arch/x86/cpu/mcheck/mce.c +++ b/xen/arch/x86/cpu/mcheck/mce.c @@ -177,6 +177,7 @@ void mce_need_clearbank_register(mce_need_clearbank_t cbfunc) static struct mce_softirq_barrier mce_inside_bar, mce_severity_bar; static struct mce_softirq_barrier mce_trap_bar; +static struct mce_softirq_barrier mce_handler_init_bar; /* * mce_logout_lock should only be used in the trap handler, @@ -187,8 +188,6 @@ static struct mce_softirq_barrier mce_trap_bar; static DEFINE_SPINLOCK(mce_logout_lock); static atomic_t severity_cpu = ATOMIC_INIT(-1); -static atomic_t found_error = ATOMIC_INIT(0); -static cpumask_t mce_fatal_cpus; const struct mca_error_handler *__read_mostly mce_dhandlers; const struct mca_error_handler *__read_mostly mce_uhandlers; @@ -453,12 +452,19 @@ static int mce_urgent_action(const struct cpu_user_regs *regs, /* Shared #MC handler. */ void mcheck_cmn_handler(const struct cpu_user_regs *regs) { + static atomic_t found_error; + static cpumask_t mce_fatal_cpus; struct mca_banks *bankmask = mca_allbanks; struct mca_banks *clear_bank = __get_cpu_var(mce_clear_banks); uint64_t gstatus; mctelem_cookie_t mctc = NULL; struct mca_summary bs; + mce_barrier_enter(&mce_handler_init_bar); + atomic_set(&found_error, 0); + cpumask_clear(&mce_fatal_cpus); + mce_barrier_exit(&mce_handler_init_bar); + mce_spin_lock(&mce_logout_lock); if (clear_bank != NULL) { @@ -1767,6 +1773,7 @@ void mce_handler_init(void) mce_barrier_init(&mce_inside_bar); mce_barrier_init(&mce_severity_bar); mce_barrier_init(&mce_trap_bar); + mce_barrier_init(&mce_handler_init_bar); spin_lock_init(&mce_logout_lock); open_softirq(MACHINE_CHECK_SOFTIRQ, mce_softirq); }
1. Move them into mcheck_cmn_handler() which is their only user. 2. Always (re-)initialize them to clear historical information. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> --- xen/arch/x86/cpu/mcheck/mce.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)