diff options
Diffstat (limited to 'arch/x86/xen/multicalls.c')
| -rw-r--r-- | arch/x86/xen/multicalls.c | 156 |
1 files changed, 148 insertions, 8 deletions
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index 5791eb2e375..8ea8a0d0b0d 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -21,22 +21,26 @@ */ #include <linux/percpu.h> #include <linux/hardirq.h> +#include <linux/debugfs.h> #include <asm/xen/hypercall.h> #include "multicalls.h" +#include "debugfs.h" + +#define MC_BATCH 32 #define MC_DEBUG 1 -#define MC_BATCH 32 -#define MC_ARGS (MC_BATCH * 16 / sizeof(u64)) +#define MC_ARGS (MC_BATCH * 16) + struct mc_buffer { struct multicall_entry entries[MC_BATCH]; #if MC_DEBUG struct multicall_entry debug[MC_BATCH]; #endif - u64 args[MC_ARGS]; + unsigned char args[MC_ARGS]; struct callback { void (*fn)(void *); void *data; @@ -47,6 +51,76 @@ struct mc_buffer { static DEFINE_PER_CPU(struct mc_buffer, mc_buffer); DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags); +/* flush reasons 0- slots, 1- args, 2- callbacks */ +enum flush_reasons +{ + FL_SLOTS, + FL_ARGS, + FL_CALLBACKS, + + FL_N_REASONS +}; + +#ifdef CONFIG_XEN_DEBUG_FS +#define NHYPERCALLS 40 /* not really */ + +static struct { + unsigned histo[MC_BATCH+1]; + + unsigned issued; + unsigned arg_total; + unsigned hypercalls; + unsigned histo_hypercalls[NHYPERCALLS]; + + unsigned flush[FL_N_REASONS]; +} mc_stats; + +static u8 zero_stats; + +static inline void check_zero(void) +{ + if (unlikely(zero_stats)) { + memset(&mc_stats, 0, sizeof(mc_stats)); + zero_stats = 0; + } +} + +static void mc_add_stats(const struct mc_buffer *mc) +{ + int i; + + check_zero(); + + mc_stats.issued++; + mc_stats.hypercalls += mc->mcidx; + mc_stats.arg_total += mc->argidx; + + mc_stats.histo[mc->mcidx]++; + for(i = 0; i < mc->mcidx; i++) { + unsigned op = mc->entries[i].op; + if (op < NHYPERCALLS) + mc_stats.histo_hypercalls[op]++; + } +} + +static void mc_stats_flush(enum flush_reasons idx) +{ + check_zero(); + + mc_stats.flush[idx]++; +} + +#else /* !CONFIG_XEN_DEBUG_FS */ + +static inline void mc_add_stats(const struct mc_buffer *mc) +{ +} + +static inline void mc_stats_flush(enum flush_reasons idx) +{ +} +#endif /* CONFIG_XEN_DEBUG_FS */ + void xen_mc_flush(void) { struct mc_buffer *b = &__get_cpu_var(mc_buffer); @@ -60,6 +134,8 @@ void xen_mc_flush(void) something in the middle */ local_irq_save(flags); + mc_add_stats(b); + if (b->mcidx) { #if MC_DEBUG memcpy(b->debug, b->entries, @@ -76,6 +152,7 @@ void xen_mc_flush(void) if (ret) { printk(KERN_ERR "%d multicall(s) failed: cpu %d\n", ret, smp_processor_id()); + dump_stack(); for (i = 0; i < b->mcidx; i++) { printk(" call %2d/%d: op=%lu arg=[%lx] result=%ld\n", i+1, b->mcidx, @@ -107,20 +184,49 @@ struct multicall_space __xen_mc_entry(size_t args) { struct mc_buffer *b = &__get_cpu_var(mc_buffer); struct multicall_space ret; - unsigned argspace = (args + sizeof(u64) - 1) / sizeof(u64); + unsigned argidx = roundup(b->argidx, sizeof(u64)); BUG_ON(preemptible()); - BUG_ON(argspace > MC_ARGS); + BUG_ON(b->argidx > MC_ARGS); if (b->mcidx == MC_BATCH || - (b->argidx + argspace) > MC_ARGS) + (argidx + args) > MC_ARGS) { + mc_stats_flush(b->mcidx == MC_BATCH ? FL_SLOTS : FL_ARGS); xen_mc_flush(); + argidx = roundup(b->argidx, sizeof(u64)); + } ret.mc = &b->entries[b->mcidx]; b->mcidx++; + ret.args = &b->args[argidx]; + b->argidx = argidx + args; + + BUG_ON(b->argidx > MC_ARGS); + return ret; +} + +struct multicall_space xen_mc_extend_args(unsigned long op, size_t size) +{ + struct mc_buffer *b = &__get_cpu_var(mc_buffer); + struct multicall_space ret = { NULL, NULL }; + + BUG_ON(preemptible()); + BUG_ON(b->argidx > MC_ARGS); + + if (b->mcidx == 0) + return ret; + + if (b->entries[b->mcidx - 1].op != op) + return ret; + + if ((b->argidx + size) > MC_ARGS) + return ret; + + ret.mc = &b->entries[b->mcidx - 1]; ret.args = &b->args[b->argidx]; - b->argidx += argspace; + b->argidx += size; + BUG_ON(b->argidx > MC_ARGS); return ret; } @@ -129,10 +235,44 @@ void xen_mc_callback(void (*fn)(void *), void *data) struct mc_buffer *b = &__get_cpu_var(mc_buffer); struct callback *cb; - if (b->cbidx == MC_BATCH) + if (b->cbidx == MC_BATCH) { + mc_stats_flush(FL_CALLBACKS); xen_mc_flush(); + } cb = &b->callbacks[b->cbidx++]; cb->fn = fn; cb->data = data; } + +#ifdef CONFIG_XEN_DEBUG_FS + +static struct dentry *d_mc_debug; + +static int __init xen_mc_debugfs(void) +{ + struct dentry *d_xen = xen_init_debugfs(); + + if (d_xen == NULL) + return -ENOMEM; + + d_mc_debug = debugfs_create_dir("multicalls", d_xen); + + debugfs_create_u8("zero_stats", 0644, d_mc_debug, &zero_stats); + + debugfs_create_u32("batches", 0444, d_mc_debug, &mc_stats.issued); + debugfs_create_u32("hypercalls", 0444, d_mc_debug, &mc_stats.hypercalls); + debugfs_create_u32("arg_total", 0444, d_mc_debug, &mc_stats.arg_total); + + xen_debugfs_create_u32_array("batch_histo", 0444, d_mc_debug, + mc_stats.histo, MC_BATCH); + xen_debugfs_create_u32_array("hypercall_histo", 0444, d_mc_debug, + mc_stats.histo_hypercalls, NHYPERCALLS); + xen_debugfs_create_u32_array("flush_reasons", 0444, d_mc_debug, + mc_stats.flush, FL_N_REASONS); + + return 0; +} +fs_initcall(xen_mc_debugfs); + +#endif /* CONFIG_XEN_DEBUG_FS */ |