From a122d6230e8d8ac7cffdf0bc9cc4b256b928fe49 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 16 Oct 2007 11:51:31 -0700 Subject: [PATCH] xen: add some debug output for failed multicalls Multicalls are expected to never fail, and the normal response to a failed multicall is very terse. In the interests of better debuggability, add some more verbose output. It may be worth turning this off once it all seems more tested. Signed-off-by: Jeremy Fitzhardinge --- arch/x86/xen/multicalls.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index ce9c4b41f02d..5e6f36f6d876 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -26,11 +26,16 @@ #include "multicalls.h" +#define MC_DEBUG 1 + #define MC_BATCH 32 #define MC_ARGS (MC_BATCH * 16 / sizeof(u64)) struct mc_buffer { struct multicall_entry entries[MC_BATCH]; +#if MC_DEBUG + struct multicall_entry debug[MC_BATCH]; +#endif u64 args[MC_ARGS]; struct callback { void (*fn)(void *); @@ -56,11 +61,31 @@ void xen_mc_flush(void) local_irq_save(flags); if (b->mcidx) { +#if MC_DEBUG + memcpy(b->debug, b->entries, + b->mcidx * sizeof(struct multicall_entry)); +#endif + if (HYPERVISOR_multicall(b->entries, b->mcidx) != 0) BUG(); for (i = 0; i < b->mcidx; i++) if (b->entries[i].result < 0) ret++; + +#if MC_DEBUG + if (ret) { + printk(KERN_ERR "%d multicall(s) failed: cpu %d\n", + ret, smp_processor_id()); + for(i = 0; i < b->mcidx; i++) { + printk(" call %2d/%d: op=%lu arg=[%lx] result=%ld\n", + i+1, b->mcidx, + b->debug[i].op, + b->debug[i].args[0], + b->entries[i].result); + } + } +#endif + b->mcidx = 0; b->argidx = 0; } else -- 2.20.1