Commit-ID: 278c9b099b2fc0cc0a51de95a1dcefcf54ca2183 Gitweb: http://git.kernel.org/tip/278c9b099b2fc0cc0a51de95a1dcefcf54ca2183 Author: tra...@sgi.com <tra...@sgi.com> AuthorDate: Wed, 25 Jan 2017 10:35:20 -0600 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 1 Feb 2017 10:20:59 +0100
x86/platform/UV: Add basic CPU NMI health check Add a low impact health check triggered by the system NMI command that essentially checks which CPUs are responding to external NMI's. Signed-off-by: Mike Travis <tra...@sgi.com> Reviewed-by: Russ Anderson <r...@hpe.com> Reviewed-by: Alex Thorlton <athorl...@sgi.com> Acked-by: Thomas Gleixner <t...@linutronix.de> Acked-by: Dimitri Sivanich <sivan...@hpe.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/20170125163517.756690...@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/platform/uv/uv_nmi.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c index df7b092..8a4aa5b 100644 --- a/arch/x86/platform/uv/uv_nmi.c +++ b/arch/x86/platform/uv/uv_nmi.c @@ -176,6 +176,7 @@ module_param_named(debug, uv_nmi_debug, int, 0644); * "kdump" - do crash dump * "kdb" - enter KDB (default) * "kgdb" - enter KGDB + * "health" - check if CPUs respond to NMI */ static char uv_nmi_action[8] = "kdb"; module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644); @@ -571,6 +572,22 @@ static void uv_nmi_sync_exit(int master) } } +/* Current "health" check is to check which CPU's are responsive */ +static void uv_nmi_action_health(int cpu, struct pt_regs *regs, int master) +{ + if (master) { + int in = atomic_read(&uv_nmi_cpus_in_nmi); + int out = num_online_cpus() - in; + + pr_alert("UV: NMI CPU health check (non-responding:%d)\n", out); + atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT); + } else { + while (!atomic_read(&uv_nmi_slave_continue)) + cpu_relax(); + } + uv_nmi_sync_exit(master); +} + /* Walk through cpu list and dump state of each */ static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master) { @@ -747,7 +764,9 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) uv_nmi_wait(master); /* Process actions other than "kdump": */ - if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) { + if (uv_nmi_action_is("health")) { + uv_nmi_action_health(cpu, regs, master); + } else if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump")) { uv_nmi_dump_state(cpu, regs, master); } else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb")) { uv_call_kgdb_kdb(cpu, regs, master);
