--- /dev/null
+/* Copyright 2005 Princeton University
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ * Redistributions in binary form must reproduce the above
+ copyright notice, this list of conditions and the following
+ disclaimer in the documentation and/or other materials provided
+ with the distribution.
+
+ * Neither the name of the copyright holder nor the names of its
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL PRINCETON
+UNIVERSITY OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
+WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/resource.h>
+
+#include "config.h"
+#include "planetlab.h"
+#include "sched_cmd.h"
+#include "virtual.h"
+#include "vserver.h"
+
+static int
+create_context(xid_t ctx, uint32_t flags, uint64_t bcaps)
+{
+ struct vc_ctx_caps vc_caps;
+
+ /*
+ * 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 flag is unset */
+ vc_caps.bcaps = bcaps;
+ vc_caps.bmask = ~0ULL; /* currently unused */
+ vc_caps.ccaps = 0; /* don't want any of these */
+ vc_caps.cmask = ~0ULL;
+ if (vc_set_ccaps(ctx, &vc_caps))
+ return -1;
+
+ /* set default scheduling parameters */
+ pl_setsched(ctx, 1, 0);
+
+ return 0;
+}
+
+int
+pl_setup_done(xid_t ctx)
+{
+ struct vc_ctx_flags vc_flags;
+
+ /* 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)
+{
+ 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))
+ {
+ if (errno == EEXIST)
+ /* another process beat us in a race */
+ goto migrate;
+ if (errno == EBUSY)
+ /* another process is creating - poll the SETUP flag */
+ continue;
+ return -1;
+ }
+
+ /* created context and migrated to it i.e., we're done */
+ 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;
+ }
+
+ /* context has been setup */
+ migrate:
+ if (!vc_ctx_migrate(ctx))
+ break; /* done */
+
+ /* context disappeared - retry */
+ }
+
+ 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;
+}
git://git.onelab.eu / util-vserver.git / blobdiff