[patch 07/38] CKRM e18: Numtasks Controller

Gerrit Huizenga
2005-06-23T07:03:18Z

[-- Attachment #1: 07-diff_numtasks --]
[-- Type: text/plain, Size: 20996 bytes --]

This patch provides a resource controller for controlling the number
of tasks per class in CKRM.

Signed-Off-By: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-Off-By: Hubertus Franke <frankeh@us.ibm.com>
Signed-Off-By: Shailabh Nagar <nagar@us.ibm.com>
Signed-Off-By: Gerrit Huizenga <gh@us.ibm.com>

include/linux/ckrm_tsk.h | 35 ++
init/Kconfig | 10
kernel/ckrm/Makefile | 3
kernel/ckrm/ckrm_numtasks.c | 522 +++++++++++++++++++++++++++++++++++++++
kernel/ckrm/ckrm_numtasks_stub.c | 53 +++
kernel/fork.c | 6
6 files changed, 628 insertions(+), 1 deletion(-)

Index: linux-2.6.12-ckrm1/include/linux/ckrm_tsk.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.12-ckrm1/include/linux/ckrm_tsk.h 2005-06-20 13:08:34.000000000 -0700
@@ -0,0 +1,35 @@
+/* ckrm_tsk.h - No. of tasks resource controller for CKRM
+ *
+ * Copyright (C) Chandra Seetharaman, IBM Corp. 2003
+ *
+ * Provides No. of tasks resource controller for CKRM
+ *
+ * Latest version, more details at http://ckrm.sf.net
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#ifndef _LINUX_CKRM_TSK_H
+#define _LINUX_CKRM_TSK_H
+
+#ifdef CONFIG_CKRM_TYPE_TASKCLASS
+#include <linux/ckrm_rc.h>
+
+typedef int (*get_ref_t) (struct ckrm_core_class *, int);
+typedef void (*put_ref_t) (struct ckrm_core_class *);
+
+extern int numtasks_get_ref(struct ckrm_core_class *, int);
+extern void numtasks_put_ref(struct ckrm_core_class *);
+extern void ckrm_numtasks_register(get_ref_t, put_ref_t);
+
+#else /* CONFIG_CKRM_TYPE_TASKCLASS */
+
+#define numtasks_get_ref(core_class, ref) (1)
+#define numtasks_put_ref(core_class) do {} while (0)
+
+#endif /* CONFIG_CKRM_TYPE_TASKCLASS */
+#endif /* _LINUX_CKRM_RES_H */
Index: linux-2.6.12-ckrm1/init/Kconfig
===================================================================
--- linux-2.6.12-ckrm1.orig/init/Kconfig 2005-06-20 13:08:32.000000000 -0700
+++ linux-2.6.12-ckrm1/init/Kconfig 2005-06-20 13:08:34.000000000 -0700
@@ -193,6 +193,16 @@ config CKRM_TYPE_SOCKETCLASS

Say Y if unsure.

+config CKRM_RES_NUMTASKS
+ tristate "Number of Tasks Resource Manager"
+ depends on CKRM_TYPE_TASKCLASS
+ default y
+ help
+ Provides a Resource Controller for CKRM that allows limiting no of
+ tasks a task class can have.
+
+ Say N if unsure, Y to use the feature.
+
endmenu

config SYSCTL
Index: linux-2.6.12-ckrm1/kernel/ckrm/ckrm_numtasks.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.12-ckrm1/kernel/ckrm/ckrm_numtasks.c 2005-06-20 13:08:34.000000000 -0700
@@ -0,0 +1,522 @@
+/* ckrm_numtasks.c - "Number of tasks" resource controller for CKRM
+ *
+ * Copyright (C) Chandra Seetharaman, IBM Corp. 2003
+ *
+ * Latest version, more details at http://ckrm.sf.net
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+/*
+ * CKRM Resource controller for tracking number of tasks in a class.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <asm/errno.h>
+#include <asm/div64.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/ckrm_rc.h>
+#include <linux/ckrm_tc.h>
+#include <linux/ckrm_tsk.h>
+
+#define TOTAL_NUM_TASKS (131072) /* 128 K */
+#define NUMTASKS_DEBUG
+#define NUMTASKS_NAME "numtasks"
+
+struct ckrm_numtasks {
+ struct ckrm_core_class *core; /* the core i am part of... */
+ struct ckrm_core_class *parent; /* parent of the core above. */
+ struct ckrm_shares shares;
+ spinlock_t cnt_lock; /* always grab parent's lock before child's */
+ int cnt_guarantee; /* num_tasks guarantee in local units */
+ int cnt_unused; /* has to borrow if more than this is needed */
+ int cnt_limit; /* no tasks over this limit. */
+ atomic_t cnt_cur_alloc; /* current alloc from self */
+ atomic_t cnt_borrowed; /* borrowed from the parent */
+
+ int over_guarantee; /* turn on/off when cur_alloc goes */
+ /* over/under guarantee */
+
+ /* internally maintained statictics to compare with max numbers */
+ int limit_failures; /* # failures as request was over the limit */
+ int borrow_sucesses; /* # successful borrows */
+ int borrow_failures; /* # borrow failures */
+
+ /* Maximum the specific statictics has reached. */
+ int max_limit_failures;
+ int max_borrow_sucesses;
+ int max_borrow_failures;
+
+ /* Total number of specific statistics */
+ int tot_limit_failures;
+ int tot_borrow_sucesses;
+ int tot_borrow_failures;
+};
+
+struct ckrm_res_ctlr numtasks_rcbs;
+
+/* Initialize rescls values
+ * May be called on each rcfs unmount or as part of error recovery
+ * to make share values sane.
+ * Does not traverse hierarchy reinitializing children.
+ */
+static void numtasks_res_initcls_one(struct ckrm_numtasks * res)
+{
+ res->shares.my_guarantee = CKRM_SHARE_DONTCARE;
+ res->shares.my_limit = CKRM_SHARE_DONTCARE;
+ res->shares.total_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
+ res->shares.max_limit = CKRM_SHARE_DFLT_MAX_LIMIT;
+ res->shares.unused_guarantee = CKRM_SHARE_DFLT_TOTAL_GUARANTEE;
+ res->shares.cur_max_limit = 0;
+
+ res->cnt_guarantee = CKRM_SHARE_DONTCARE;
+ res->cnt_unused = CKRM_SHARE_DONTCARE;
+ res->cnt_limit = CKRM_SHARE_DONTCARE;
+
+ res->over_guarantee = 0;
+
+ res->limit_failures = 0;
+ res->borrow_sucesses = 0;
+ res->borrow_failures = 0;
+
+ res->max_limit_failures = 0;
+ res->max_borrow_sucesses = 0;
+ res->max_borrow_failures = 0;
+
+ res->tot_limit_failures = 0;
+ res->tot_borrow_sucesses = 0;
+ res->tot_borrow_failures = 0;
+
+ atomic_set(&res->cnt_cur_alloc, 0);
+ atomic_set(&res->cnt_borrowed, 0);
+ return;
+}
+
+#if 0
+static void numtasks_res_initcls(void *my_res)
+{
+ struct ckrm_numtasks *res = my_res;
+
+ /* Write a version which propagates values all the way down
+ and replace rcbs callback with that version */
+
+}
+#endif
+
+static int numtasks_get_ref_local(struct ckrm_core_class *core, int force)
+{
+ int rc, resid = numtasks_rcbs.resid;
+ struct ckrm_numtasks *res;
+
+ if ((resid < 0) || (core == NULL))
+ return 1;
+
+ res = ckrm_get_res_class(core, resid, struct ckrm_numtasks);
+ if (res == NULL)
+ return 1;
+
+ atomic_inc(&res->cnt_cur_alloc);
+
+ rc = 1;
+ if (((res->parent) && (res->cnt_unused == CKRM_SHARE_DONTCARE)) ||
+ (atomic_read(&res->cnt_cur_alloc) > res->cnt_unused)) {
+
+ rc = 0;
+ if (!force && (res->cnt_limit != CKRM_SHARE_DONTCARE) &&
+ (atomic_read(&res->cnt_cur_alloc) > res->cnt_limit)) {
+ res->limit_failures++;
+ res->tot_limit_failures++;
+ } else if (res->parent != NULL) {
+ if ((rc =
+ numtasks_get_ref_local(res->parent, force)) == 1) {
+ atomic_inc(&res->cnt_borrowed);
+ res->borrow_sucesses++;
+ res->tot_borrow_sucesses++;
+ res->over_guarantee = 1;
+ } else {
+ res->borrow_failures++;
+ res->tot_borrow_failures++;
+ }
+ } else {
+ rc = force;
+ }
+ } else if (res->over_guarantee) {
+ res->over_guarantee = 0;
+
+ if (res->max_limit_failures < res->limit_failures) {
+ res->max_limit_failures = res->limit_failures;
+ }
+ if (res->max_borrow_sucesses < res->borrow_sucesses) {
+ res->max_borrow_sucesses = res->borrow_sucesses;
+ }
+ if (res->max_borrow_failures < res->borrow_failures) {
+ res->max_borrow_failures = res->borrow_failures;
+ }
+ res->limit_failures = 0;
+ res->borrow_sucesses = 0;
+ res->borrow_failures = 0;
+ }
+
+ if (!rc) {
+ atomic_dec(&res->cnt_cur_alloc);
+ }
+ return rc;
+}
+
+static void numtasks_put_ref_local(struct ckrm_core_class *core)
+{
+ int resid = numtasks_rcbs.resid;
+ struct ckrm_numtasks *res;
+
+ if ((resid == -1) || (core == NULL)) {
+ return;
+ }
+
+ res = ckrm_get_res_class(core, resid, struct ckrm_numtasks);
+ if (res == NULL)
+ return;
+ if (unlikely(atomic_read(&res->cnt_cur_alloc) == 0)) {
+ printk(KERN_WARNING "numtasks_put_ref: Trying to decrement "
+ "counter below 0\n");
+ return;
+ }
+ atomic_dec(&res->cnt_cur_alloc);
+ if (atomic_read(&res->cnt_borrowed) > 0) {
+ atomic_dec(&res->cnt_borrowed);
+ numtasks_put_ref_local(res->parent);
+ }
+ return;
+}
+
+static void *numtasks_res_alloc(struct ckrm_core_class *core,
+ struct ckrm_core_class *parent)
+{
+ struct ckrm_numtasks *res;
+
+ res = kmalloc(sizeof(struct ckrm_numtasks), GFP_ATOMIC);
+
+ if (res) {
+ memset(res, 0, sizeof(struct ckrm_numtasks));
+ res->core = core;
+ res->parent = parent;
+ numtasks_res_initcls_one(res);
+ res->cnt_lock = SPIN_LOCK_UNLOCKED;
+ if (parent == NULL) {
+ /*
+ * I am part of root class. So set the max tasks
+ * to available default.
+ */
+ res->cnt_guarantee = TOTAL_NUM_TASKS;
+ res->cnt_unused = TOTAL_NUM_TASKS;
+ res->cnt_limit = TOTAL_NUM_TASKS;
+ }
+ try_module_get(THIS_MODULE);
+ } else {
+ printk(KERN_ERR
+ "numtasks_res_alloc: failed GFP_ATOMIC alloc\n");
+ }
+ return res;
+}
+
+/*
+ * No locking of this resource class object necessary as we are not
+ * supposed to be assigned (or used) when/after this function is called.
+ */
+static void numtasks_res_free(void *my_res)
+{
+ struct ckrm_numtasks *res = my_res, *parres, *childres;
+ struct ckrm_core_class *child = NULL;
+ int i, borrowed, maxlimit, resid = numtasks_rcbs.resid;
+
+ if (!res)
+ return;
+
+ /* Assuming there will be no children when this function is called */
+
+ parres = ckrm_get_res_class(res->parent, resid, struct ckrm_numtasks);
+
+ if (unlikely(atomic_read(&res->cnt_cur_alloc) < 0)) {
+ printk(KERN_WARNING "numtasks_res: counter below 0\n");
+ }
+ if (unlikely(atomic_read(&res->cnt_cur_alloc) > 0 ||
+ atomic_read(&res->cnt_borrowed) > 0)) {
+ printk(KERN_WARNING "numtasks_res_free: resource still "
+ "alloc'd %p\n", res);
+ if ((borrowed = atomic_read(&res->cnt_borrowed)) > 0) {
+ for (i = 0; i < borrowed; i++) {
+ numtasks_put_ref_local(parres->core);
+ }
+ }
+ }
+ /* return child's limit/guarantee to parent node */
+ spin_lock(&parres->cnt_lock);
+ child_guarantee_changed(&parres->shares, res->shares.my_guarantee, 0);
+
+ /* run thru parent's children and get the new max_limit of the parent */
+ ckrm_lock_hier(parres->core);
+ maxlimit = 0;
+ while ((child = ckrm_get_next_child(parres->core, child)) != NULL) {
+ childres = ckrm_get_res_class(child, resid, struct ckrm_numtasks);
+ if (maxlimit < childres->shares.my_limit) {
+ maxlimit = childres->shares.my_limit;
+ }
+ }
+ ckrm_unlock_hier(parres->core);
+ if (parres->shares.cur_max_limit < maxlimit) {
+ parres->shares.cur_max_limit = maxlimit;
+ }
+
+ spin_unlock(&parres->cnt_lock);
+ kfree(res);
+ module_put(THIS_MODULE);
+ return;
+}
+
+/*
+ * Recalculate the guarantee and limit in real units... and propagate the
+ * same to children.
+ * Caller is responsible for protecting res and for the integrity of parres
+ */
+static void
+recalc_and_propagate(struct ckrm_numtasks * res, struct ckrm_numtasks * parres)
+{
+ struct ckrm_core_class *child = NULL;
+ struct ckrm_numtasks *childres;
+ int resid = numtasks_rcbs.resid;
+
+ if (parres) {
+ struct ckrm_shares *par = &parres->shares;
+ struct ckrm_shares *self = &res->shares;
+
+ /* calculate cnt_guarantee and cnt_limit */
+ if (parres->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ res->cnt_guarantee = CKRM_SHARE_DONTCARE;
+ } else if (par->total_guarantee) {
+ u64 temp = (u64) self->my_guarantee * parres->cnt_guarantee;
+ do_div(temp, par->total_guarantee);
+ res->cnt_guarantee = (int) temp;
+ } else {
+ res->cnt_guarantee = 0;
+ }
+
+ if (parres->cnt_limit == CKRM_SHARE_DONTCARE) {
+ res->cnt_limit = CKRM_SHARE_DONTCARE;
+ } else if (par->max_limit) {
+ u64 temp = (u64) self->my_limit * parres->cnt_limit;
+ do_div(temp, par->max_limit);
+ res->cnt_limit = (int) temp;
+ } else {
+ res->cnt_limit = 0;
+ }
+
+ /* Calculate unused units */
+ if (res->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ res->cnt_unused = CKRM_SHARE_DONTCARE;
+ } else if (self->total_guarantee) {
+ u64 temp = (u64) self->unused_guarantee * res->cnt_guarantee;
+ do_div(temp, self->total_guarantee);
+ res->cnt_unused = (int) temp;
+ } else {
+ res->cnt_unused = 0;
+ }
+ }
+ /* propagate to children */
+ ckrm_lock_hier(res->core);
+ while ((child = ckrm_get_next_child(res->core, child)) != NULL) {
+ childres = ckrm_get_res_class(child, resid, struct ckrm_numtasks);
+
+ spin_lock(&childres->cnt_lock);
+ recalc_and_propagate(childres, res);
+ spin_unlock(&childres->cnt_lock);
+ }
+ ckrm_unlock_hier(res->core);
+ return;
+}
+
+static int numtasks_set_share_values(void *my_res, struct ckrm_shares *new)
+{
+ struct ckrm_numtasks *parres, *res = my_res;
+ struct ckrm_shares *cur = &res->shares, *par;
+ int rc = -EINVAL, resid = numtasks_rcbs.resid;
+
+ if (!res)
+ return rc;
+
+ if (res->parent) {
+ parres =
+ ckrm_get_res_class(res->parent, resid, struct ckrm_numtasks);
+ spin_lock(&parres->cnt_lock);
+ spin_lock(&res->cnt_lock);
+ par = &parres->shares;
+ } else {
+ spin_lock(&res->cnt_lock);
+ par = NULL;
+ parres = NULL;
+ }
+
+ rc = set_shares(new, cur, par);
+
+ if ((rc == 0) && parres) {
+ /* Calculate parent's unused units */
+ if (parres->cnt_guarantee == CKRM_SHARE_DONTCARE) {
+ parres->cnt_unused = CKRM_SHARE_DONTCARE;
+ } else if (par->total_guarantee) {
+ u64 temp = (u64) par->unused_guarantee * parres->cnt_guarantee;
+ do_div(temp, par->total_guarantee);
+ parres->cnt_unused = (int) temp;
+ } else {
+ parres->cnt_unused = 0;
+ }
+ recalc_and_propagate(res, parres);
+ }
+ spin_unlock(&res->cnt_lock);
+ if (res->parent) {
+ spin_unlock(&parres->cnt_lock);
+ }
+ return rc;
+}
+
+static int numtasks_get_share_values(void *my_res, struct ckrm_shares *shares)
+{
+ struct ckrm_numtasks *res = my_res;
+
+ if (!res)
+ return -EINVAL;
+ *shares = res->shares;
+ return 0;
+}
+
+static int numtasks_get_stats(void *my_res, struct seq_file *sfile)
+{
+ struct ckrm_numtasks *res = my_res;
+
+ if (!res)
+ return -EINVAL;
+
+ seq_printf(sfile, "Number of tasks resource:\n");
+ seq_printf(sfile, "Total Over limit failures: %d\n",
+ res->tot_limit_failures);
+ seq_printf(sfile, "Total Over guarantee sucesses: %d\n",
+ res->tot_borrow_sucesses);
+ seq_printf(sfile, "Total Over guarantee failures: %d\n",
+ res->tot_borrow_failures);
+
+ seq_printf(sfile, "Maximum Over limit failures: %d\n",
+ res->max_limit_failures);
+ seq_printf(sfile, "Maximum Over guarantee sucesses: %d\n",
+ res->max_borrow_sucesses);
+ seq_printf(sfile, "Maximum Over guarantee failures: %d\n",
+ res->max_borrow_failures);
+#ifdef NUMTASKS_DEBUG
+ seq_printf(sfile,
+ "cur_alloc %d; borrowed %d; cnt_guar %d; cnt_limit %d "
+ "cnt_unused %d, unused_guarantee %d, cur_max_limit %d\n",
+ atomic_read(&res->cnt_cur_alloc),
+ atomic_read(&res->cnt_borrowed), res->cnt_guarantee,
+ res->cnt_limit, res->cnt_unused,
+ res->shares.unused_guarantee,
+ res->shares.cur_max_limit);
+#endif
+
+ return 0;
+}
+
+static int numtasks_show_config(void *my_res, struct seq_file *sfile)
+{
+ struct ckrm_numtasks *res = my_res;
+
+ if (!res)
+ return -EINVAL;
+
+ seq_printf(sfile, "res=%s,parameter=somevalue\n", NUMTASKS_NAME);
+ return 0;
+}
+
+static int numtasks_set_config(void *my_res, const char *cfgstr)
+{
+ struct ckrm_numtasks *res = my_res;
+
+ if (!res)
+ return -EINVAL;
+ printk("numtasks config='%s'\n", cfgstr);
+ return 0;
+}
+
+static void numtasks_change_resclass(void *task, void *old, void *new)
+{
+ struct ckrm_numtasks *oldres = old;
+ struct ckrm_numtasks *newres = new;
+
+ if (oldres != (void *)-1) {
+ struct task_struct *tsk = task;
+ if (!oldres) {
+ struct ckrm_core_class *old_core =
+ &(tsk->parent->taskclass->core);
+ oldres =
+ ckrm_get_res_class(old_core, numtasks_rcbs.resid,
+ struct ckrm_numtasks);
+ }
+ numtasks_put_ref_local(oldres->core);
+ }
+ if (newres) {
+ (void)numtasks_get_ref_local(newres->core, 1);
+ }
+}
+
+struct ckrm_res_ctlr numtasks_rcbs = {
+ .res_name = NUMTASKS_NAME,
+ .res_hdepth = 1,
+ .resid = -1,
+ .res_alloc = numtasks_res_alloc,
+ .res_free = numtasks_res_free,
+ .set_share_values = numtasks_set_share_values,
+ .get_share_values = numtasks_get_share_values,
+ .get_stats = numtasks_get_stats,
+ .show_config = numtasks_show_config,
+ .set_config = numtasks_set_config,
+ .change_resclass = numtasks_change_resclass,
+};
+
+int __init init_ckrm_numtasks_res(void)
+{
+ struct ckrm_classtype *clstype;
+ int resid = numtasks_rcbs.resid;
+
+ clstype = ckrm_find_classtype_by_name("taskclass");
+ if (clstype == NULL) {
+ printk(KERN_INFO " Unknown ckrm classtype<taskclass>");
+ return -ENOENT;
+ }
+
+ if (resid == -1) {
+ resid = ckrm_register_res_ctlr(clstype, &numtasks_rcbs);
+ printk("........init_ckrm_numtasks_res -> %d\n", resid);
+ if (resid != -1) {
+ ckrm_numtasks_register(numtasks_get_ref_local,
+ numtasks_put_ref_local);
+ numtasks_rcbs.classtype = clstype;
+ }
+ }
+ return 0;
+}
+
+void __exit exit_ckrm_numtasks_res(void)
+{
+ if (numtasks_rcbs.resid != -1) {
+ ckrm_numtasks_register(NULL, NULL);
+ }
+ ckrm_unregister_res_ctlr(&numtasks_rcbs);
+ numtasks_rcbs.resid = -1;
+}
+
+module_init(init_ckrm_numtasks_res)
+module_exit(exit_ckrm_numtasks_res)
+
+MODULE_LICENSE("GPL");
Index: linux-2.6.12-ckrm1/kernel/ckrm/ckrm_numtasks_stub.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.12-ckrm1/kernel/ckrm/ckrm_numtasks_stub.c 2005-06-20 13:08:34.000000000 -0700
@@ -0,0 +1,53 @@
+/* ckrm_tasks_stub.c - Stub file for ckrm_tasks modules
+ *
+ * Copyright (C) Chandra Seetharaman, IBM Corp. 2004
+ *
+ * Latest version, more details at http://ckrm.sf.net
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/ckrm_tsk.h>
+
+static spinlock_t stub_lock = SPIN_LOCK_UNLOCKED;
+
+static get_ref_t real_get_ref = NULL;
+static put_ref_t real_put_ref = NULL;
+
+void ckrm_numtasks_register(get_ref_t gr, put_ref_t pr)
+{
+ spin_lock(&stub_lock);
+ real_get_ref = gr;
+ real_put_ref = pr;
+ spin_unlock(&stub_lock);
+}
+
+int numtasks_get_ref(struct ckrm_core_class *arg, int force)
+{
+ int ret = 1;
+ spin_lock(&stub_lock);
+ if (real_get_ref) {
+ ret = (*real_get_ref) (arg, force);
+ }
+ spin_unlock(&stub_lock);
+ return ret;
+}
+
+void numtasks_put_ref(struct ckrm_core_class *arg)
+{
+ spin_lock(&stub_lock);
+ if (real_put_ref) {
+ (*real_put_ref) (arg);
+ }
+ spin_unlock(&stub_lock);
+}
+
+EXPORT_SYMBOL(ckrm_numtasks_register);
+EXPORT_SYMBOL(numtasks_get_ref);
+EXPORT_SYMBOL(numtasks_put_ref);
Index: linux-2.6.12-ckrm1/kernel/ckrm/Makefile
===================================================================
--- linux-2.6.12-ckrm1.orig/kernel/ckrm/Makefile 2005-06-20 13:08:32.000000000 -0700
+++ linux-2.6.12-ckrm1/kernel/ckrm/Makefile 2005-06-20 13:08:34.000000000 -0700
@@ -3,5 +3,6 @@
#

obj-y += ckrm_events.o ckrm.o ckrmutils.o
-obj-$(CONFIG_CKRM_TYPE_TASKCLASS) += ckrm_tc.o
+obj-$(CONFIG_CKRM_TYPE_TASKCLASS) += ckrm_tc.o ckrm_numtasks_stub.o
obj-$(CONFIG_CKRM_TYPE_SOCKETCLASS) += ckrm_sockc.o
+obj-$(CONFIG_CKRM_RES_NUMTASKS) += ckrm_numtasks.o
Index: linux-2.6.12-ckrm1/kernel/fork.c
===================================================================
--- linux-2.6.12-ckrm1.orig/kernel/fork.c 2005-06-20 13:08:27.000000000 -0700
+++ linux-2.6.12-ckrm1/kernel/fork.c 2005-06-20 13:08:34.000000000 -0700
@@ -42,6 +42,8 @@
#include <linux/rmap.h>
#include <linux/acct.h>
#include <linux/ckrm_events.h>
+#include <linux/ckrm_tsk.h>
+#include <linux/ckrm_tc.h>

#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -1211,6 +1213,9 @@ long do_fork(unsigned long clone_flags,
clone_flags |= CLONE_PTRACE;
}

+ if (numtasks_get_ref(&current->taskclass->core, 0) == 0) {
+ return -ENOMEM;
+ }
p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
/*
* Do this prior waking up the new thread - the thread pointer
@@ -1250,6 +1255,7 @@ long do_fork(unsigned long clone_flags,
ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
}
} else {
+ numtasks_put_ref(&current->taskclass->core);
free_pidmap(pid);
pid = PTR_ERR(p);
}

--