[RFC PATCH 10/14] mm/hbind: add heterogeneous memory policy tracking infrastructure
From: jglisse
Date: Mon Dec 03 2018 - 18:36:21 EST
From: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
This patch add infrastructure to track heterogeneous memory policy
within the kernel. Policy are defined over range of virtual address
of a process and attach to the correspond mm_struct.
User can reset to default policy for range of virtual address using
hbind() default commands for the range.
Signed-off-by: JÃrÃme Glisse <jglisse@xxxxxxxxxx>
Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Haggai Eran <haggaie@xxxxxxxxxxxx>
Cc: Balbir Singh <balbirs@xxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Felix Kuehling <felix.kuehling@xxxxxxx>
Cc: Philip Yang <Philip.Yang@xxxxxxx>
Cc: Christian KÃnig <christian.koenig@xxxxxxx>
Cc: Paul Blinzer <Paul.Blinzer@xxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
Cc: Mark Hairgrove <mhairgrove@xxxxxxxxxx>
Cc: Vivek Kini <vkini@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxxxx>
Cc: Ben Skeggs <bskeggs@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
include/linux/hms.h | 46 ++++++
include/linux/mm_types.h | 6 +
include/uapi/linux/hbind.h | 8 +
kernel/fork.c | 3 +
mm/hms.c | 306 ++++++++++++++++++++++++++++++++++++-
5 files changed, 368 insertions(+), 1 deletion(-)
diff --git a/include/linux/hms.h b/include/linux/hms.h
index 511b5363d8f2..f39c390b3afb 100644
--- a/include/linux/hms.h
+++ b/include/linux/hms.h
@@ -20,6 +20,8 @@
#include <linux/device.h>
#include <linux/types.h>
+#include <linux/mm_types.h>
+#include <linux/mmu_notifier.h>
struct hms_target;
@@ -34,6 +36,10 @@ struct hms_target_hbind {
#if IS_ENABLED(CONFIG_HMS)
+#include <linux/interval_tree.h>
+#include <linux/rwsem.h>
+
+
#define to_hms_object(device) container_of(device, struct hms_object, device)
enum hms_type {
@@ -133,6 +139,42 @@ void hms_bridge_register(struct hms_bridge **bridgep,
void hms_bridge_unregister(struct hms_bridge **bridgep);
+struct hms_policy_targets {
+ struct hms_target **targets;
+ unsigned ntargets;
+ struct kref kref;
+};
+
+struct hms_policy_range {
+ struct hms_policy_targets *ptargets;
+ struct interval_tree_node node;
+ struct kref kref;
+};
+
+struct hms_policy {
+ struct rb_root_cached ranges;
+ struct rw_semaphore sem;
+ struct mmu_notifier mn;
+};
+
+static inline unsigned long hms_policy_range_start(struct hms_policy_range *r)
+{
+ return r->node.start;
+}
+
+static inline unsigned long hms_policy_range_end(struct hms_policy_range *r)
+{
+ return r->node.last + 1;
+}
+
+static inline void hms_policy_init(struct mm_struct *mm)
+{
+ mm->hpolicy = NULL;
+}
+
+void hms_policy_fini(struct mm_struct *mm);
+
+
int hms_init(void);
@@ -163,6 +205,10 @@ int hms_init(void);
#define hms_bridge_unregister(bridgep)
+#define hms_policy_init(mm)
+#define hms_policy_fini(mm)
+
+
static inline int hms_init(void)
{
return 0;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 5ed8f6292a53..3da91767c689 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -26,6 +26,7 @@ typedef int vm_fault_t;
struct address_space;
struct mem_cgroup;
+struct hms_policy;
struct hmm;
/*
@@ -491,6 +492,11 @@ struct mm_struct {
/* HMM needs to track a few things per mm */
struct hmm *hmm;
#endif
+
+#if IS_ENABLED(CONFIG_HMS)
+ /* Heterogeneous Memory System policy */
+ struct hms_policy *hpolicy;
+#endif
} __randomize_layout;
/*
diff --git a/include/uapi/linux/hbind.h b/include/uapi/linux/hbind.h
index a9aba17ab142..cc4687587f5a 100644
--- a/include/uapi/linux/hbind.h
+++ b/include/uapi/linux/hbind.h
@@ -39,6 +39,14 @@ struct hbind_params {
#define HBIND_ATOM_GET_CMD(v) ((v) & 0xfffff)
#define HBIND_ATOM_SET_CMD(v) ((v) & 0xfffff)
+/*
+ * HBIND_CMD_DEFAULT restore default policy ie undo any of the previous policy.
+ *
+ * Additional dwords:
+ * NONE (DWORDS MUST BE 0 !)
+ */
+#define HBIND_CMD_DEFAULT 0
+
#define HBIND_IOCTL _IOWR('H', 0x00, struct hbind_params)
diff --git a/kernel/fork.c b/kernel/fork.c
index 07cddff89c7b..bc40edcadc69 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -38,6 +38,7 @@
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
#include <linux/hmm.h>
+#include <linux/hms.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/vmacache.h>
@@ -671,6 +672,7 @@ void __mmdrop(struct mm_struct *mm)
mm_free_pgd(mm);
destroy_context(mm);
hmm_mm_destroy(mm);
+ hms_policy_fini(mm);
mmu_notifier_mm_destroy(mm);
check_mm(mm);
put_user_ns(mm->user_ns);
@@ -989,6 +991,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
RCU_INIT_POINTER(mm->exe_file, NULL);
mmu_notifier_mm_init(mm);
hmm_mm_init(mm);
+ hms_policy_init(mm);
init_tlb_flush_pending(mm);
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
diff --git a/mm/hms.c b/mm/hms.c
index bf328bd577dc..be2c4e526f25 100644
--- a/mm/hms.c
+++ b/mm/hms.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/hms.h>
+#include <linux/mm.h>
#include <linux/fs.h>
#include <uapi/linux/hbind.h>
@@ -31,7 +32,6 @@
#define HBIND_FIX_ARRAY 64
-
static ssize_t hbind_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
@@ -44,6 +44,300 @@ static ssize_t hbind_write(struct file *file, const char __user *buf,
return -EINVAL;
}
+
+static void hms_policy_targets_get(struct hms_policy_targets *ptargets)
+{
+ kref_get(&ptargets->kref);
+}
+
+static void hms_policy_targets_free(struct kref *kref)
+{
+ struct hms_policy_targets *ptargets;
+
+ ptargets = container_of(kref, struct hms_policy_targets, kref);
+ kfree(ptargets->targets);
+ kfree(ptargets);
+}
+
+static void hms_policy_targets_put(struct hms_policy_targets *ptargets)
+{
+ kref_put(&ptargets->kref, &hms_policy_targets_free);
+}
+
+static struct hms_policy_targets* hms_policy_targets_new(const uint32_t *targets,
+ unsigned ntargets)
+{
+ struct hms_policy_targets *ptargets;
+ void *_targets;
+ unsigned i, c;
+
+ _targets = kzalloc(ntargets * sizeof(void *), GFP_KERNEL);
+ if (_targets == NULL)
+ return NULL;
+
+ ptargets = kmalloc(sizeof(*ptargets), GFP_KERNEL);
+ if (ptargets == NULL) {
+ kfree(_targets);
+ return NULL;
+ }
+
+ kref_init(&ptargets->kref);
+ ptargets->targets = _targets;
+ ptargets->ntargets = ntargets;
+
+ for (i = 0, c = 0; i < ntargets; ++i) {
+ ptargets->targets[c] = hms_target_find(targets[i]);
+ c += !!((long)ptargets->targets[i]);
+ }
+
+ /* Ignore NULL targets[i] */
+ ptargets->ntargets = c;
+
+ if (!c) {
+ /* No valid targets pointless to waste memory ... */
+ hms_policy_targets_put(ptargets);
+ return NULL;
+ }
+
+ return ptargets;
+}
+
+
+static void hms_policy_range_get(struct hms_policy_range *prange)
+{
+ kref_get(&prange->kref);
+}
+
+static void hms_policy_range_free(struct kref *kref)
+{
+ struct hms_policy_range *prange;
+
+ prange = container_of(kref, struct hms_policy_range, kref);
+ hms_policy_targets_put(prange->ptargets);
+ kfree(prange);
+}
+
+static void hms_policy_range_put(struct hms_policy_range *prange)
+{
+ kref_put(&prange->kref, &hms_policy_range_free);
+}
+
+static struct hms_policy_range *hms_policy_range_new(const uint32_t *targets,
+ unsigned long start,
+ unsigned long end,
+ unsigned ntargets)
+{
+ struct hms_policy_targets *ptargets;
+ struct hms_policy_range *prange;
+
+ ptargets = hms_policy_targets_new(targets, ntargets);
+ if (ptargets == NULL)
+ return NULL;
+
+ prange = kmalloc(sizeof(*prange), GFP_KERNEL);
+ if (prange == NULL)
+ return NULL;
+
+ prange->node.start = start & PAGE_MASK;
+ prange->node.last = PAGE_ALIGN(end) - 1;
+ prange->ptargets = ptargets;
+ kref_init(&prange->kref);
+
+ return prange;
+}
+
+static struct hms_policy_range *
+hms_policy_range_dup(struct hms_policy_range *_prange)
+{
+ struct hms_policy_range *prange;
+
+ prange = kmalloc(sizeof(*prange), GFP_KERNEL);
+ if (prange == NULL)
+ return NULL;
+
+ hms_policy_targets_get(_prange->ptargets);
+ prange->node.start = _prange->node.start;
+ prange->node.last = _prange->node.last;
+ prange->ptargets = _prange->ptargets;
+ kref_init(&prange->kref);
+
+ return prange;
+}
+
+
+void hms_policy_fini(struct mm_struct *mm)
+{
+ struct hms_policy *hpolicy = READ_ONCE(mm->hpolicy);
+ struct interval_tree_node *node;
+
+ spin_lock(&mm->page_table_lock);
+ hpolicy = READ_ONCE(mm->hpolicy);
+ mm->hpolicy = NULL;
+ spin_unlock(&mm->page_table_lock);
+
+ /* No active heterogeneous policy structure so nothing to cleanup. */
+ if (hpolicy == NULL)
+ return;
+
+ mmu_notifier_unregister_no_release(&hpolicy->mn, mm);
+
+ down_write(&hpolicy->sem);
+ node = interval_tree_iter_first(&hpolicy->ranges, 0, -1UL);
+ while (node) {
+ struct hms_policy_range *prange;
+ struct interval_tree_node *next;
+
+ prange = container_of(node, struct hms_policy_range, node);
+ next = interval_tree_iter_next(node, 0, -1UL);
+ interval_tree_remove(node, &hpolicy->ranges);
+ hms_policy_range_put(prange);
+ node = next;
+ }
+ up_write(&hpolicy->sem);
+
+ kfree(hpolicy);
+}
+
+
+static int hbind_default_locked(struct hms_policy *hpolicy,
+ struct hbind_params *params)
+{
+ struct interval_tree_node *node;
+ unsigned long start, last;
+ int ret = 0;
+
+ start = params->start;
+ last = params->end - 1UL;
+
+ node = interval_tree_iter_first(&hpolicy->ranges, start, last);
+ while (node) {
+ struct hms_policy_range *prange;
+ struct interval_tree_node *next;
+
+ prange = container_of(node, struct hms_policy_range, node);
+ next = interval_tree_iter_next(node, start, last);
+ if (node->start < start && node->last > last) {
+ /* Node is split in 2 */
+ struct hms_policy_range *_prange;
+ _prange = hms_policy_range_dup(prange);
+ if (_prange == NULL) {
+ ret = -ENOMEM;
+ break;
+ }
+ prange->node.last = start - 1;
+ _prange->node.start = last + 1;
+ interval_tree_insert(&_prange->node, &hpolicy->ranges);
+ break;
+ } else if (node->start < start) {
+ prange->node.last = start - 1;
+ } else if (node->last > last) {
+ prange->node.start = last + 1;
+ } else {
+ /* Fully inside [start, last] */
+ interval_tree_remove(node, &hpolicy->ranges);
+ }
+
+ node = next;
+ }
+
+ return ret;
+}
+
+static int hbind_default(struct mm_struct *mm, struct hbind_params *params,
+ const uint32_t *targets, uint32_t *atoms)
+{
+ struct hms_policy *hpolicy = READ_ONCE(mm->hpolicy);
+ int ret;
+
+ /* No active heterogeneous policy structure so no range to reset. */
+ if (hpolicy == NULL)
+ return 0;
+
+ down_write(&hpolicy->sem);
+ ret = hbind_default_locked(hpolicy, params);
+ up_write(&hpolicy->sem);
+
+ return ret;
+}
+
+
+static void hms_policy_notifier_release(struct mmu_notifier *mn,
+ struct mm_struct *mm)
+{
+ hms_policy_fini(mm);
+}
+
+static int hms_policy_notifier_invalidate_range_start(struct mmu_notifier *mn,
+ const struct mmu_notifier_range *range)
+{
+ if (range->event == MMU_NOTIFY_UNMAP) {
+ struct hbind_params params;
+
+ if (!range->blockable)
+ return -EBUSY;
+
+ params.natoms = 0;
+ params.ntargets = 0;
+ params.end = range->end;
+ params.start = range->start;
+ hbind_default(range->mm, ¶ms, NULL, NULL);
+ }
+
+ return 0;
+}
+
+static const struct mmu_notifier_ops hms_policy_notifier_ops = {
+ .release = hms_policy_notifier_release,
+ .invalidate_range_start = hms_policy_notifier_invalidate_range_start,
+};
+
+static struct hms_policy *hms_policy_get(struct mm_struct *mm)
+{
+ struct hms_policy *hpolicy = READ_ONCE(mm->hpolicy);
+ bool mmu_notifier = false;
+
+ /*
+ * The hpolicy struct can only be freed once the mm_struct goes away,
+ * hence only pre-allocate if none is attach yet.
+ */
+ if (hpolicy)
+ return hpolicy;
+
+ hpolicy = kzalloc(sizeof(*hpolicy), GFP_KERNEL);
+ if (hpolicy == NULL)
+ return NULL;
+
+ init_rwsem(&hpolicy->sem);
+
+ spin_lock(&mm->page_table_lock);
+ if (!mm->hpolicy) {
+ mm->hpolicy = hpolicy;
+ mmu_notifier = true;
+ hpolicy = NULL;
+ }
+ spin_unlock(&mm->page_table_lock);
+
+ if (mmu_notifier) {
+ int ret;
+
+ hpolicy->mn.ops = &hms_policy_notifier_ops;
+ ret = mmu_notifier_register(&hpolicy->mn, mm);
+ if (ret) {
+ spin_lock(&mm->page_table_lock);
+ hpolicy = mm->hpolicy;
+ mm->hpolicy = NULL;
+ spin_unlock(&mm->page_table_lock);
+ }
+ }
+
+ if (hpolicy)
+ kfree(hpolicy);
+
+ /* At this point mm->hpolicy is valid */
+ return mm->hpolicy;
+}
+
+
static long hbind_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
uint32_t *targets, *_dtargets = NULL, _ftargets[HBIND_FIX_ARRAY];
@@ -114,6 +408,16 @@ static long hbind_ioctl(struct file *file, unsigned cmd, unsigned long arg)
for (i = 0, ndwords = 1; i < params.natoms; i += ndwords) {
ndwords = 1 + HBIND_ATOM_GET_DWORDS(atoms[i]);
switch (HBIND_ATOM_GET_CMD(atoms[i])) {
+ case HBIND_CMD_DEFAULT:
+ if (ndwords != 1) {
+ ret = -EINVAL;
+ goto out_mm;
+ }
+ ret = hbind_default(current->mm, ¶ms,
+ targets, atoms);
+ if (ret)
+ goto out_mm;
+ break;
default:
ret = -EINVAL;
goto out_mm;
--
2.17.2