This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / kernel / vserver / monitor.c

diff --git a/kernel/vserver/monitor.c b/kernel/vserver/monitor.c
new file mode 100644 (file)
index 0000000..ac8e2e6
--- /dev/null
+++ b/kernel/vserver/monitor.c
@@ -0,0 +1,142 @@
+/*
+ *  kernel/vserver/monitor.c
+ *
+ *  Virtual Context Scheduler Monitor
+ *
+ *  Copyright (C) 2006-2007 Herbert Pötzl
+ *
+ *  V0.01  basic design
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+
+#include <asm/uaccess.h>
+#include <asm/atomic.h>
+#include <asm/unistd.h>
+
+#include <linux/vserver/monitor.h>
+#include <linux/vserver/debug_cmd.h>
+
+
+#ifdef CONFIG_VSERVER_MONITOR
+#define VXM_SIZE       CONFIG_VSERVER_MONITOR_SIZE
+#else
+#define VXM_SIZE       64
+#endif
+
+struct _vx_monitor {
+       unsigned int counter;
+
+       struct _vx_mon_entry entry[VXM_SIZE+1];
+};
+
+
+DEFINE_PER_CPU(struct _vx_monitor, vx_monitor_buffer);
+
+unsigned volatile int vxm_active = 1;
+
+static atomic_t sequence = ATOMIC_INIT(0);
+
+
+/*     vxm_advance()
+
+       * requires disabled preemption                          */
+
+struct _vx_mon_entry *vxm_advance(int cpu)
+{
+       struct _vx_monitor *mon = &per_cpu(vx_monitor_buffer, cpu);
+       struct _vx_mon_entry *entry;
+       unsigned int index;
+
+       index = vxm_active ? (mon->counter++ % VXM_SIZE) : VXM_SIZE;
+       entry = &mon->entry[index];
+
+       entry->ev.seq = atomic_inc_return(&sequence);
+       entry->ev.jif = jiffies;
+       return entry;
+}
+
+EXPORT_SYMBOL_GPL(vxm_advance);
+
+
+int do_read_monitor(struct __user _vx_mon_entry *data,
+       int cpu, uint32_t *index, uint32_t *count)
+{
+       int pos, ret = 0;
+       struct _vx_monitor *mon = &per_cpu(vx_monitor_buffer, cpu);
+       int end = mon->counter;
+       int start = end - VXM_SIZE + 2;
+       int idx = *index;
+
+       /* special case: get current pos */
+       if (!*count) {
+               *index = end;
+               return 0;
+       }
+
+       /* have we lost some data? */
+       if (idx < start)
+               idx = start;
+
+       for (pos = 0; (pos < *count) && (idx < end); pos++, idx++) {
+               struct _vx_mon_entry *entry =
+                       &mon->entry[idx % VXM_SIZE];
+
+               /* send entry to userspace */
+               ret = copy_to_user (&data[pos], entry, sizeof(*entry));
+               if (ret)
+                       break;
+       }
+       /* save new index and count */
+       *index = idx;
+       *count = pos;
+       return ret ? ret : (*index < end);
+}
+
+int vc_read_monitor(uint32_t id, void __user *data)
+{
+       struct vcmd_read_monitor_v0 vc_data;
+       int ret;
+
+       if (id >= NR_CPUS)
+               return -EINVAL;
+
+       if (copy_from_user (&vc_data, data, sizeof(vc_data)))
+               return -EFAULT;
+
+       ret = do_read_monitor((struct __user _vx_mon_entry *)vc_data.data,
+               id, &vc_data.index, &vc_data.count);
+
+       if (copy_to_user (data, &vc_data, sizeof(vc_data)))
+               return -EFAULT;
+       return ret;
+}
+
+#ifdef CONFIG_COMPAT
+
+int vc_read_monitor_x32(uint32_t id, void __user *data)
+{
+       struct vcmd_read_monitor_v0_x32 vc_data;
+       int ret;
+
+       if (id >= NR_CPUS)
+               return -EINVAL;
+
+       if (copy_from_user (&vc_data, data, sizeof(vc_data)))
+               return -EFAULT;
+
+       ret = do_read_monitor((struct __user _vx_mon_entry *)
+               compat_ptr(vc_data.data_ptr),
+               id, &vc_data.index, &vc_data.count);
+
+       if (copy_to_user (data, &vc_data, sizeof(vc_data)))
+               return -EFAULT;
+       return ret;
+}
+
+#endif /* CONFIG_COMPAT */
+