From: "T.J. Alumbaugh" <[email protected]>
Add working set and notification vqueues, along with a
simple interface to kernel WS functions. The driver receives
config info and sends reports on notification. A mutex is
used to guard virtio_balloon state.
Signed-off-by: T.J. Alumbaugh <[email protected]>
Signed-off-by: Yuanchu Xie <[email protected]>
---
drivers/virtio/virtio_balloon.c | 288 ++++++++++++++++++++++++++++
include/linux/balloon_compaction.h | 3 +
include/linux/wsr.h | 29 ++-
include/uapi/linux/virtio_balloon.h | 33 ++++
mm/vmscan.c | 106 ++++++++++
5 files changed, 457 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 3f78a3a1eb753..0cb6a46eb7e8a 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -11,6 +11,7 @@
#include <linux/swap.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/balloon_compaction.h>
@@ -45,6 +46,8 @@ enum virtio_balloon_vq {
VIRTIO_BALLOON_VQ_STATS,
VIRTIO_BALLOON_VQ_FREE_PAGE,
VIRTIO_BALLOON_VQ_REPORTING,
+ VIRTIO_BALLOON_VQ_WORKING_SET,
+ VIRTIO_BALLOON_VQ_NOTIFY,
VIRTIO_BALLOON_VQ_MAX
};
@@ -55,6 +58,9 @@ enum virtio_balloon_config_read {
struct virtio_balloon {
struct virtio_device *vdev;
struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
+#ifdef CONFIG_WSR
+ struct virtqueue *working_set_vq, *notification_vq;
+#endif
/* Balloon's own wq for cpu-intensive work items */
struct workqueue_struct *balloon_wq;
@@ -64,6 +70,10 @@ struct virtio_balloon {
/* The balloon servicing is delegated to a freezable workqueue. */
struct work_struct update_balloon_stats_work;
struct work_struct update_balloon_size_work;
+#ifdef CONFIG_WSR
+ struct work_struct update_balloon_working_set_work;
+ struct work_struct update_balloon_notification_work;
+#endif
/* Prevent updating balloon when it is being canceled. */
spinlock_t stop_update_lock;
@@ -119,6 +129,16 @@ struct virtio_balloon {
/* Free page reporting device */
struct virtqueue *reporting_vq;
struct page_reporting_dev_info pr_dev_info;
+
+#ifdef CONFIG_WSR
+ /* Working Set reporting */
+ u8 working_set_num_bins;
+ struct virtio_balloon_working_set *working_set;
+
+ /* A buffer to hold incoming notification from the host. */
+ unsigned int notification_size;
+ void *notification_buf;
+#endif
};
static const struct virtio_device_id id_table[] = {
@@ -465,6 +485,211 @@ static void update_balloon_stats_func(struct work_struct *work)
stats_handle_request(vb);
}
+#ifdef CONFIG_WSR
+/* Must hold the balloon_lock while calling this function. */
+static inline void reset_working_set(struct virtio_balloon *vb)
+{
+ int i;
+
+ for (i = 0; i < vb->working_set_num_bins; ++i) {
+ vb->working_set[i].tag = cpu_to_virtio16(vb->vdev, -1);
+ vb->working_set[i].node_id = cpu_to_virtio16(vb->vdev, -1);
+ vb->working_set[i].idle_age_ms = cpu_to_virtio64(vb->vdev, 0);
+ vb->working_set[i].memory_size_bytes[0] = cpu_to_virtio64(vb->vdev, -1);
+ vb->working_set[i].memory_size_bytes[1] = cpu_to_virtio64(vb->vdev, -1);
+ }
+}
+
+/* Must hold the balloon_lock while calling this function. */
+static inline void update_working_set(struct virtio_balloon *vb, int idx,
+ u64 idle_age, u64 bytes_anon,
+ u64 bytes_file, int node_id)
+{
+ vb->working_set[idx].tag = cpu_to_virtio16(vb->vdev, VIRTIO_BALLOON_WS_RECLAIMABLE);
+ vb->working_set[idx].node_id = cpu_to_virtio16(vb->vdev, node_id);
+ vb->working_set[idx].idle_age_ms = cpu_to_virtio64(vb->vdev, idle_age);
+ vb->working_set[idx].memory_size_bytes[0] = cpu_to_virtio64(vb->vdev,
+ bytes_anon);
+ vb->working_set[idx].memory_size_bytes[1] = cpu_to_virtio64(vb->vdev,
+ bytes_file);
+}
+
+static bool working_set_is_init(struct virtio_balloon *vb)
+{
+ if (vb->working_set[0].idle_age_ms > 0)
+ return true;
+ return false;
+}
+
+static void virtio_balloon_working_set_request(void)
+{
+ struct pglist_data *pgdat;
+ int nid = NUMA_NO_NODE;
+
+ if (IS_ENABLED(CONFIG_NUMA)) {
+ for_each_online_node(nid) {
+ if (node_possible(nid)) {
+ pgdat = NODE_DATA(nid);
+ working_set_request(pgdat);
+ }
+ }
+ } else {
+ pgdat = NODE_DATA(nid);
+ working_set_request(pgdat);
+ }
+}
+
+static void notification_receive(struct virtqueue *vq)
+{
+ struct virtio_balloon *vb = vq->vdev->priv;
+
+ spin_lock(&vb->stop_update_lock);
+ if (!vb->stop_update)
+ queue_work(system_freezable_wq, &vb->update_balloon_notification_work);
+ spin_unlock(&vb->stop_update_lock);
+}
+
+static int virtio_balloon_register_working_set_receiver(struct virtio_balloon *vb,
+ __virtio64 *intervals, unsigned long nr_bins, __virtio64 refresh_ms,
+ __virtio64 report_ms)
+{
+ struct pglist_data *pgdat;
+ unsigned long *bin_intervals = NULL;
+ int i, err;
+ int nid = NUMA_NO_NODE;
+
+ if (intervals && nr_bins) {
+ /* TODO: keep values as 32-bits throughout. */
+ bin_intervals = kzalloc(sizeof(unsigned long) * (nr_bins-1),
+ GFP_KERNEL);
+ for (i = 0; i < nr_bins - 1; i++)
+ bin_intervals[i] = (unsigned long)intervals[i];
+
+ if (IS_ENABLED(CONFIG_NUMA)) {
+ for_each_online_node(nid) {
+ if (node_possible(nid)) {
+ pgdat = NODE_DATA(nid);
+ err = register_working_set_receiver(vb,
+ pgdat, &(bin_intervals[0]),
+ nr_bins, (unsigned long) refresh_ms,
+ (unsigned long) report_ms);
+ }
+ }
+ } else {
+ pgdat = NODE_DATA(nid);
+ err = register_working_set_receiver(vb, pgdat,
+ &(bin_intervals[0]), nr_bins,
+ (unsigned long) refresh_ms,
+ (unsigned long) report_ms);
+ }
+ kfree(bin_intervals);
+ return err;
+ }
+ return -EINVAL;
+}
+
+void working_set_notify(void *ws_receiver, struct ws_bin *bins, int node_id)
+{
+ u64 bytes_nr_file, bytes_nr_anon;
+ struct virtio_balloon *vb = ws_receiver;
+ int idx = 0;
+
+ if (!mutex_trylock(&vb->balloon_lock))
+ return;
+ for (; idx < vb->working_set_num_bins; idx++) {
+ bytes_nr_anon = (u64)(bins[idx].nr_pages[0]) * PAGE_SIZE;
+ bytes_nr_file = (u64)(bins[idx].nr_pages[1]) * PAGE_SIZE;
+ update_working_set(vb, idx, jiffies_to_msecs(bins[idx].idle_age),
+ bytes_nr_anon, bytes_nr_file, node_id);
+ }
+ mutex_unlock(&vb->balloon_lock);
+ /* Send the working set report to the device. */
+ spin_lock(&vb->stop_update_lock);
+ if (!vb->stop_update)
+ queue_work(system_freezable_wq, &vb->update_balloon_working_set_work);
+ spin_unlock(&vb->stop_update_lock);
+}
+EXPORT_SYMBOL(working_set_notify);
+
+static void update_balloon_notification_func(struct work_struct *work)
+{
+ struct virtio_balloon *vb;
+ struct scatterlist sg_in;
+ struct pglist_data *pgdat;
+ __virtio64 *bin_intervals;
+ __virtio64 refresh_ms, report_ms;
+ int16_t tag;
+ char *buf;
+ int len;
+
+ vb = container_of(work, struct virtio_balloon,
+ update_balloon_notification_work);
+
+ /* Read a Working Set notification from the device. */
+ buf = (char *)vb->notification_buf;
+ tag = *((int16_t *)buf);
+ buf += sizeof(int16_t);
+ if (tag == VIRTIO_BALLOON_WS_REQUEST) {
+ pgdat = NODE_DATA(NUMA_NO_NODE);
+ virtio_balloon_working_set_request();
+ } else if (tag == VIRTIO_BALLOON_WS_CONFIG) {
+ mutex_lock(&vb->balloon_lock);
+ reset_working_set(vb);
+ mutex_unlock(&vb->balloon_lock);
+ bin_intervals = (__virtio64 *) buf;
+ buf += sizeof(__virtio64) * (vb->working_set_num_bins - 1);
+ refresh_ms = *((__virtio64 *) buf);
+ buf += sizeof(__virtio64);
+ report_ms = *((__virtio64 *) buf);
+ virtio_balloon_register_working_set_receiver(vb, bin_intervals,
+ vb->working_set_num_bins, refresh_ms, report_ms);
+ } else {
+ dev_warn(&vb->vdev->dev, "Received invalid notification, %u\n", tag);
+ return;
+ }
+
+ /* Detach all the used buffers from the vq */
+ while (virtqueue_get_buf(vb->notification_vq, &len))
+ ;
+ /* Add a new notification buffer for device to fill. */
+ sg_init_one(&sg_in, vb->notification_buf, vb->notification_size);
+ virtqueue_add_inbuf(vb->notification_vq, &sg_in, 1, vb, GFP_KERNEL);
+ virtqueue_kick(vb->notification_vq);
+}
+
+static void update_balloon_ws_func(struct work_struct *work)
+{
+ struct virtio_balloon *vb;
+ struct scatterlist sg_out;
+ int err = 0;
+ int unused;
+
+ vb = container_of(work, struct virtio_balloon,
+ update_balloon_working_set_work);
+
+ mutex_lock(&vb->balloon_lock);
+ if (working_set_is_init(vb)) {
+ /* Detach all the used buffers from the vq */
+ while (virtqueue_get_buf(vb->working_set_vq, &unused))
+ ;
+ sg_init_one(&sg_out, vb->working_set,
+ (sizeof(struct virtio_balloon_working_set) *
+ vb->working_set_num_bins));
+ err = virtqueue_add_outbuf(vb->working_set_vq, &sg_out, 1, vb, GFP_KERNEL);
+ } else {
+ dev_warn(&vb->vdev->dev, "Working Set not initialized.");
+ err = -EINVAL;
+ }
+ mutex_unlock(&vb->balloon_lock);
+ if (unlikely(err)) {
+ dev_err(&vb->vdev->dev,
+ "Failed to send working set report err = %d\n", err);
+ } else {
+ virtqueue_kick(vb->working_set_vq);
+ }
+}
+#endif /* CONFIG_WSR */
+
static void update_balloon_size_func(struct work_struct *work)
{
struct virtio_balloon *vb;
@@ -508,6 +733,10 @@ static int init_vqs(struct virtio_balloon *vb)
callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
names[VIRTIO_BALLOON_VQ_REPORTING] = NULL;
+ callbacks[VIRTIO_BALLOON_VQ_WORKING_SET] = NULL;
+ names[VIRTIO_BALLOON_VQ_WORKING_SET] = NULL;
+ callbacks[VIRTIO_BALLOON_VQ_NOTIFY] = NULL;
+ names[VIRTIO_BALLOON_VQ_NOTIFY] = NULL;
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
names[VIRTIO_BALLOON_VQ_STATS] = "stats";
@@ -524,6 +753,15 @@ static int init_vqs(struct virtio_balloon *vb)
callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack;
}
+#ifdef CONFIG_WSR
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING)) {
+ names[VIRTIO_BALLOON_VQ_WORKING_SET] = "ws";
+ callbacks[VIRTIO_BALLOON_VQ_WORKING_SET] = NULL;
+ names[VIRTIO_BALLOON_VQ_NOTIFY] = "notify";
+ callbacks[VIRTIO_BALLOON_VQ_NOTIFY] = notification_receive;
+ }
+#endif
+
err = virtio_find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, vqs,
callbacks, names, NULL);
if (err)
@@ -534,6 +772,7 @@ static int init_vqs(struct virtio_balloon *vb)
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
struct scatterlist sg;
unsigned int num_stats;
+
vb->stats_vq = vqs[VIRTIO_BALLOON_VQ_STATS];
/*
@@ -553,6 +792,25 @@ static int init_vqs(struct virtio_balloon *vb)
virtqueue_kick(vb->stats_vq);
}
+#ifdef CONFIG_WSR
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING)) {
+ struct scatterlist sg;
+
+ vb->working_set_vq = vqs[VIRTIO_BALLOON_VQ_WORKING_SET];
+ vb->notification_vq = vqs[VIRTIO_BALLOON_VQ_NOTIFY];
+
+ /* Prime the notification virtqueue for the device to fill.*/
+ sg_init_one(&sg, vb->notification_buf, vb->notification_size);
+ err = virtqueue_add_inbuf(vb->notification_vq, &sg, 1, vb, GFP_KERNEL);
+ if (unlikely(err)) {
+ dev_err(&vb->vdev->dev,
+ "Failed to prepare notifications, err = %d\n", err);
+ } else {
+ virtqueue_kick(vb->notification_vq);
+ }
+ }
+#endif
+
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
vb->free_page_vq = vqs[VIRTIO_BALLOON_VQ_FREE_PAGE];
@@ -878,6 +1136,10 @@ static int virtballoon_probe(struct virtio_device *vdev)
INIT_WORK(&vb->update_balloon_stats_work, update_balloon_stats_func);
INIT_WORK(&vb->update_balloon_size_work, update_balloon_size_func);
+#ifdef CONFIG_WSR
+ INIT_WORK(&vb->update_balloon_working_set_work, update_balloon_ws_func);
+ INIT_WORK(&vb->update_balloon_notification_work, update_balloon_notification_func);
+#endif
spin_lock_init(&vb->stop_update_lock);
mutex_init(&vb->balloon_lock);
init_waitqueue_head(&vb->acked);
@@ -885,6 +1147,23 @@ static int virtballoon_probe(struct virtio_device *vdev)
balloon_devinfo_init(&vb->vb_dev_info);
+#ifdef CONFIG_WSR
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_WS_REPORTING)) {
+ virtio_cread_le(vdev, struct virtio_balloon_config, working_set_num_bins,
+ &vb->working_set_num_bins);
+ dev_err(&vb->vdev->dev, "in probe , num bins: %d ", vb->working_set_num_bins);
+ /* Allocate space for a Working Set report. */
+ vb->working_set = kcalloc(vb->working_set_num_bins,
+ sizeof(struct virtio_balloon_working_set), GFP_KERNEL);
+ /* Allocate space for host notifications. */
+ vb->notification_size =
+ sizeof(uint16_t) +
+ sizeof(uint64_t) * (vb->working_set_num_bins + 1);
+ vb->notification_buf = kzalloc(vb->notification_size, GFP_KERNEL);
+ reset_working_set(vb);
+ }
+#endif
+
err = init_vqs(vb);
if (err)
goto out_free_vb;
@@ -1034,11 +1313,19 @@ static void virtballoon_remove(struct virtio_device *vdev)
unregister_oom_notifier(&vb->oom_nb);
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
virtio_balloon_unregister_shrinker(vb);
+#ifdef CONFIG_WSR
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING))
+ unregister_working_set_receiver(vb);
+#endif
spin_lock_irq(&vb->stop_update_lock);
vb->stop_update = true;
spin_unlock_irq(&vb->stop_update_lock);
cancel_work_sync(&vb->update_balloon_size_work);
cancel_work_sync(&vb->update_balloon_stats_work);
+#ifdef CONFIG_WSR
+ cancel_work_sync(&vb->update_balloon_working_set_work);
+ cancel_work_sync(&vb->update_balloon_notification_work);
+#endif
if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
cancel_work_sync(&vb->report_free_page_work);
@@ -1104,6 +1391,7 @@ static unsigned int features[] = {
VIRTIO_BALLOON_F_FREE_PAGE_HINT,
VIRTIO_BALLOON_F_PAGE_POISON,
VIRTIO_BALLOON_F_REPORTING,
+ VIRTIO_BALLOON_F_WS_REPORTING,
};
static struct virtio_driver virtio_balloon_driver = {
diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
index 5ca2d56996201..7bbf5281d84d3 100644
--- a/include/linux/balloon_compaction.h
+++ b/include/linux/balloon_compaction.h
@@ -43,6 +43,7 @@
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/list.h>
+#include <linux/mmzone.h>
/*
* Balloon device information descriptor.
@@ -67,6 +68,8 @@ extern size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
struct list_head *pages);
extern size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
struct list_head *pages, size_t n_req_pages);
+extern void working_set_notify(void *ws_receiver, struct ws_bin *bins,
+ int node_id);
static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
{
diff --git a/include/linux/wsr.h b/include/linux/wsr.h
index 68246734679cd..671ca5426254d 100644
--- a/include/linux/wsr.h
+++ b/include/linux/wsr.h
@@ -53,6 +53,16 @@ void wsr_refresh(struct wsr *wsr, struct mem_cgroup *root,
struct pglist_data *pgdat);
void report_reaccess(struct lruvec *lruvec, struct lru_gen_mm_walk *walk);
void report_ws(struct pglist_data *pgdat, struct scan_control *sc);
+/*
+ * Function to send the working set report to a receiver (e.g. the balloon driver)
+ * TODO: Replace with a proper registration interface, similar to shrinkers.
+ */
+int register_working_set_receiver(void *receiver, struct pglist_data *pgdat,
+ unsigned long *intervals, unsigned long nr_bins,
+ unsigned long report_threshold,
+ unsigned long refresh_threshold);
+void unregister_working_set_receiver(void *receiver);
+bool working_set_request(struct pglist_data *pgdat);
#else
struct ws_bin;
struct wsr;
@@ -84,6 +94,21 @@ static inline void report_reaccess(struct lruvec *lruvec, struct lru_gen_mm_walk
static inline void report_ws(struct pglist_data *pgdat, struct scan_control *sc)
{
}
-#endif /* CONFIG_WSR */
+static inline int
+register_working_set_receiver(void *receiver, struct pglist_data *pgdat,
+ unsigned long *intervals, unsigned long nr_bins,
+ unsigned long report_threshold,
+ unsigned long refresh_threshold)
+{
+ return -EINVAL;
+}
+static inline void unregister_working_set_receiver(void *receiver)
+{
+}
+static inline bool working_set_request(struct pglist_data *pgdat)
+{
+ return false;
+}
+#endif /* CONFIG_WSR */
-#endif /* _LINUX_WSR_H */
+#endif /* _LINUX_WSR_H */
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index ddaa45e723c4c..a682d917daca1 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -37,6 +37,7 @@
#define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
#define VIRTIO_BALLOON_F_REPORTING 5 /* Page reporting virtqueue */
+#define VIRTIO_BALLOON_F_WS_REPORTING 6 /* Working Set Size reporting */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
@@ -59,6 +60,9 @@ struct virtio_balloon_config {
};
/* Stores PAGE_POISON if page poisoning is in use */
__le32 poison_val;
+ /* Number of bins for Working Set report if in use. */
+ __u8 working_set_num_bins;
+ __u8 padding[3];
};
#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */
@@ -116,4 +120,33 @@ struct virtio_balloon_stat {
__virtio64 val;
} __attribute__((packed));
+/* Enumerate all possible message types from the device. */
+enum virtio_balloon_working_set_op {
+ VIRTIO_BALLOON_WS_REQUEST = 1,
+ VIRTIO_BALLOON_WS_CONFIG = 2,
+};
+
+/* The metadata values for Working Set Reports. */
+enum virtio_balloon_working_set_tags {
+ /* Memory is reclaimable by guest */
+ VIRTIO_BALLOON_WS_RECLAIMABLE = 0,
+ /* Memory can only be discarded by guest */
+ VIRTIO_BALLOON_WS_DISCARDABLE = 1,
+};
+
+/*
+ * Working Set Report structure.
+ */
+struct virtio_balloon_working_set {
+ /* A tag for additional metadata. */
+ __le16 tag;
+ /* the NUMA node for this report. */
+ __le16 node_id;
+ uint8_t reserved[4];
+ /* The idle age (in ms) of this bin of memory */
+ __virtio64 idle_age_ms;
+ /* A bin each for anonymous and file-backed memory. */
+ __le64 memory_size_bytes[2];
+};
+
#endif /* _LINUX_VIRTIO_BALLOON_H */
diff --git a/mm/vmscan.c b/mm/vmscan.c
index bc8c026ceef0d..c89728f8f61ba 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -5911,6 +5911,57 @@ late_initcall(init_lru_gen);
******************************************************************************/
#ifdef CONFIG_WSR
+static void *wsr_receiver;
+
+/*
+ * Register/unregister a receiver of working set notifications
+ * TODO: Replace with a proper registration interface, similar to shrinkers.
+ */
+int register_working_set_receiver(void *receiver, struct pglist_data *pgdat,
+ unsigned long *intervals,
+ unsigned long nr_bins,
+ unsigned long refresh_threshold,
+ unsigned long report_threshold)
+{
+ struct wsr *wsr;
+ struct ws_bin *bins;
+ int i;
+
+ wsr_receiver = receiver;
+
+ if (!pgdat)
+ return 0;
+
+ if (!intervals || !nr_bins)
+ return 0;
+
+ bins = kzalloc(sizeof(wsr->bins), GFP_KERNEL);
+ if (!bins)
+ return -ENOMEM;
+
+ for (i = 0; i < nr_bins - 1; i++) {
+ bins[i].idle_age = msecs_to_jiffies(*intervals);
+ intervals++;
+ }
+ bins[i].idle_age = -1;
+
+ wsr = lruvec_wsr(mem_cgroup_lruvec(NULL, pgdat));
+
+ mutex_lock(&wsr->bins_lock);
+ memcpy(wsr->bins, bins, sizeof(wsr->bins));
+ WRITE_ONCE(wsr->refresh_threshold, msecs_to_jiffies(refresh_threshold));
+ WRITE_ONCE(wsr->report_threshold, msecs_to_jiffies(report_threshold));
+ mutex_unlock(&wsr->bins_lock);
+ return 0;
+}
+EXPORT_SYMBOL(register_working_set_receiver);
+
+void unregister_working_set_receiver(void *receiver)
+{
+ wsr_receiver = NULL;
+}
+EXPORT_SYMBOL(unregister_working_set_receiver);
+
void wsr_refresh(struct wsr *wsr, struct mem_cgroup *root,
struct pglist_data *pgdat)
{
@@ -5967,6 +6018,16 @@ void report_ws(struct pglist_data *pgdat, struct scan_control *sc)
refresh_wsr(wsr, memcg, pgdat, sc, 0);
WRITE_ONCE(wsr->timestamp, jiffies);
+ /* Balloon driver subscribes to global memory reclaim.
+ * This requires CONFIG_VIRTIO_BALLOON=y, not m, because
+ * it's calling a function defined in virtio_balloon.c.
+ * This is a hack to have balloon notifications work in a
+ * proof of concept, and aproper notification registration
+ * interface is on the TODO list.
+ */
+ if (!cgroup_reclaim(sc) && wsr_receiver)
+ working_set_notify(wsr_receiver, wsr->bins, pgdat->node_id);
+
mutex_unlock(&wsr->bins_lock);
if (wsr->notifier)
@@ -5974,6 +6035,51 @@ void report_ws(struct pglist_data *pgdat, struct scan_control *sc)
if (memcg && cmpxchg(&memcg->wsr_event, 0, 1) == 0)
wake_up_interruptible(&memcg->wsr_wait_queue);
}
+
+/* TODO: Replace with a proper registration interface, similar to shrinkers. */
+bool working_set_request(struct pglist_data *pgdat)
+{
+ unsigned int flags;
+ struct scan_control sc = {
+ .may_writepage = true,
+ .may_unmap = true,
+ .may_swap = true,
+ .reclaim_idx = MAX_NR_ZONES - 1,
+ .gfp_mask = GFP_KERNEL,
+ };
+ struct wsr *wsr;
+
+ if (!wsr_receiver)
+ return false;
+
+ wsr = lruvec_wsr(mem_cgroup_lruvec(NULL, pgdat));
+
+ if (!mutex_trylock(&wsr->bins_lock))
+ return false;
+
+ if (wsr->bins->idle_age != -1) {
+ unsigned long timestamp = READ_ONCE(wsr->timestamp);
+ unsigned long threshold = READ_ONCE(wsr->refresh_threshold);
+
+ if (time_is_before_jiffies(timestamp + threshold)) {
+ // We might need to refresh the report.
+ set_task_reclaim_state(current, &sc.reclaim_state);
+ flags = memalloc_noreclaim_save();
+ refresh_wsr(wsr, NULL, pgdat, &sc, threshold);
+ memalloc_noreclaim_restore(flags);
+ set_task_reclaim_state(current, NULL);
+ }
+ }
+
+ if (wsr_receiver)
+ working_set_notify(wsr_receiver, wsr->bins, pgdat->node_id);
+
+ mutex_unlock(&wsr->bins_lock);
+ return true;
+
+}
+EXPORT_SYMBOL(working_set_request);
+
#endif /* CONFIG_WSR */
#else /* !CONFIG_LRU_GEN */
--
2.41.0.162.gfafddb0af9-goog