#include <errno.h>
#include <stdint.h>
+#include <stdio.h>
#include <unistd.h>
#include <sys/resource.h>
#include "vserver.h"
static int
-create_context(xid_t ctx, uint32_t flags, uint64_t bcaps, const rspec_t *rspec)
+create_context(xid_t ctx, uint32_t flags, uint64_t bcaps)
{
struct vc_ctx_caps vc_caps;
- struct vc_ctx_flags vc_flags;
- struct vc_set_sched vc_sched;
- struct vc_rlimit vc_rlimit;
- /* create context info */
+ /*
+ * Create context info - this sets the STATE_SETUP and STATE_INIT flags.
+ * Don't ever clear the STATE_INIT flag, that makes us the init task.
+ *
+ * XXX - the kernel code allows initial flags to be passed as an arg.
+ */
if (vc_ctx_create(ctx) == VC_NOCTX)
return -1;
- /* set capabilities - these don't take effect until SETUP flags is unset */
+ /* set capabilities - these don't take effect until SETUP flag is unset */
vc_caps.bcaps = bcaps;
vc_caps.bmask = ~0ULL; /* currently unused */
vc_caps.ccaps = 0; /* don't want any of these */
if (vc_set_ccaps(ctx, &vc_caps))
return -1;
- /* ignore all flags except SETUP and scheduler flags */
- vc_flags.mask = VC_VXF_STATE_SETUP | VC_VXF_SCHED_FLAGS;
- /* don't let user change scheduler flags */
- vc_flags.flagword = flags & ~VC_VXF_SCHED_FLAGS; /* SETUP not set */
+ /* set default scheduling parameters */
+ pl_setsched(ctx, 32, 0);
- /* set scheduler parameters */
- vc_flags.flagword |= rspec->cpu_sched_flags;
- vc_sched.set_mask = (VC_VXSM_FILL_RATE | VC_VXSM_INTERVAL | VC_VXSM_TOKENS |
- VC_VXSM_TOKENS_MIN | VC_VXSM_TOKENS_MAX);
- vc_sched.fill_rate = rspec->cpu_share; /* tokens accumulated per interval */
- vc_sched.interval = 1000; /* milliseconds */
- vc_sched.tokens = 100; /* initial allocation of tokens */
- vc_sched.tokens_min = 50; /* need this many tokens to run */
- vc_sched.tokens_max = 100; /* max accumulated number of tokens */
- if (vc_set_sched(ctx, &vc_sched))
- return -1;
-
- /* set resource limits */
- vc_rlimit.min = VC_LIM_KEEP;
- vc_rlimit.soft = VC_LIM_KEEP;
- vc_rlimit.hard = rspec->mem_limit;
- if (vc_set_rlimit(ctx, RLIMIT_RSS, &vc_rlimit))
- return -1;
+ return 0;
+}
- /* assume min and soft unchanged by set_rlimit */
- vc_rlimit.hard = rspec->task_limit;
- if (vc_set_rlimit(ctx, RLIMIT_NPROC, &vc_rlimit))
- return -1;
+int
+pl_setup_done(xid_t ctx)
+{
+ struct vc_ctx_flags vc_flags;
- /* set flags, unset SETUP flag - this allows other processes to migrate */
+ /* unset SETUP flag - this allows other processes to migrate */
+ vc_flags.mask = VC_VXF_STATE_SETUP;
+ vc_flags.flagword = 0;
if (vc_set_cflags(ctx, &vc_flags))
return -1;
return 0;
}
+#define RETRY_LIMIT 10
+
int
-pl_chcontext(xid_t ctx, uint32_t flags, uint64_t bcaps, const rspec_t *rspec)
+pl_chcontext(xid_t ctx, uint32_t flags, uint64_t bcaps)
{
+ int retry_count = 0;
+
for (;;)
{
struct vc_ctx_flags vc_flags;
if (vc_get_cflags(ctx, &vc_flags))
{
+ if (errno != ESRCH)
+ return -1;
+
/* context doesn't exist - create it */
- if (create_context(ctx, flags, bcaps, rspec))
+ if (create_context(ctx, flags, bcaps))
{
if (errno == EEXIST)
/* another process beat us in a race */
}
/* created context and migrated to it i.e., we're done */
- break;
+ return 1;
}
/* check the SETUP flag */
if (vc_flags.flagword & VC_VXF_STATE_SETUP)
{
/* context is still being setup - wait a while then retry */
+ if (retry_count++ >= RETRY_LIMIT)
+ {
+ errno = EBUSY;
+ return -1;
+ }
sleep(1);
continue;
}
return 0;
}
+
+/* it's okay for a syscall to fail because the context doesn't exist */
+#define VC_SYSCALL(x) \
+do \
+{ \
+ if (x) \
+ return errno == ESRCH ? 0 : -1; \
+} \
+while (0)
+
+int
+pl_setsched(xid_t ctx, uint32_t cpu_share, uint32_t cpu_sched_flags)
+{
+ struct vc_set_sched vc_sched;
+ struct vc_ctx_flags vc_flags;
+ uint32_t new_flags;
+
+ vc_sched.set_mask = (VC_VXSM_FILL_RATE | VC_VXSM_INTERVAL | VC_VXSM_TOKENS |
+ VC_VXSM_TOKENS_MIN | VC_VXSM_TOKENS_MAX);
+ vc_sched.fill_rate = cpu_share; /* tokens accumulated per interval */
+ vc_sched.interval = 1000; /* milliseconds */
+ vc_sched.tokens = 100; /* initial allocation of tokens */
+ vc_sched.tokens_min = 50; /* need this many tokens to run */
+ vc_sched.tokens_max = 100; /* max accumulated number of tokens */
+
+ VC_SYSCALL(vc_set_sched(ctx, &vc_sched));
+
+ /* get current flag values */
+ VC_SYSCALL(vc_get_cflags(ctx, &vc_flags));
+
+ /* guaranteed CPU corresponds to SCHED_SHARE flag being cleared */
+ new_flags = (cpu_sched_flags & VS_SCHED_CPU_GUARANTEED
+ ? 0
+ : VC_VXF_SCHED_SHARE);
+ if ((vc_flags.flagword & VC_VXF_SCHED_SHARE) != new_flags)
+ {
+ vc_flags.mask = VC_VXF_SCHED_FLAGS;
+ vc_flags.flagword = new_flags | VC_VXF_SCHED_HARD;
+ VC_SYSCALL(vc_set_cflags(ctx, &vc_flags));
+ }
+
+ return 0;
+}