*/
#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];
+ void *caller[MC_BATCH];
#endif
- u64 args[MC_ARGS];
+ unsigned char args[MC_ARGS];
struct callback {
void (*fn)(void *);
void *data;
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);
something in the middle */
local_irq_save(flags);
+ mc_add_stats(b);
+
if (b->mcidx) {
#if MC_DEBUG
memcpy(b->debug, b->entries,
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",
+ printk(KERN_DEBUG " call %2d/%d: op=%lu arg=[%lx] result=%ld\t%pF\n",
i+1, b->mcidx,
b->debug[i].op,
b->debug[i].args[0],
- b->entries[i].result);
+ b->entries[i].result,
+ b->caller[i]);
}
}
#endif
} else
BUG_ON(b->argidx != 0);
- local_irq_restore(flags);
-
for (i = 0; i < b->cbidx; i++) {
struct callback *cb = &b->callbacks[i];
}
b->cbidx = 0;
- BUG_ON(ret);
+ local_irq_restore(flags);
+
+ WARN_ON(ret);
}
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];
+#ifdef MC_DEBUG
+ b->caller[b->mcidx] = __builtin_return_address(0);
+#endif
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;
}
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 */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff