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/i386/xen/multicalls.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) =================================================================== --- a/arch/i386/xen/multicalls.c +++ b/arch/i386/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 -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/