For completeness, the corresponding QEMU device change is here: https://lists.gnu.org/archive/html/qemu-devel/2023-05/msg02503.html and the proposed VIRTIO spec change is here: https://lists.oasis-open.org/archives/virtio-comment/202305/msg00227.html I think some of the more fundamental questions about the driver change might be best handled on virtio-comment and/or virtio-dev. Thanks, -T.J. On Tue, May 9, 2023 at 12:54 PM Yuanchu Xie <yuanchu@xxxxxxxxxx> wrote: > > From: talumbau <talumbau@xxxxxxxxxx> > > - Add WS and notification vqueues > - Add simple interface to kernel WS functions > - Driver receives config info and sends reports on notification > - use mutex to guard virtio_balloon state > > Signed-off-by: T.J. Alumbaugh <talumbau@xxxxxxxxxx> > Signed-off-by: Yuanchu Xie <yuanchu@xxxxxxxxxx> > --- > drivers/virtio/virtio_balloon.c | 243 +++++++++++++++++++++++++++- > include/linux/balloon_compaction.h | 6 + > include/uapi/linux/virtio_balloon.h | 21 +++ > mm/vmscan.c | 102 ++++++++++++ > 4 files changed, 371 insertions(+), 1 deletion(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index 3f78a3a1eb75..edfa2a4960a3 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> > @@ -39,12 +40,22 @@ > (1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT)) > #define VIRTIO_BALLOON_HINT_BLOCK_PAGES (1 << VIRTIO_BALLOON_HINT_BLOCK_ORDER) > > +/* TODO: replace with a registration interface, similar to shrinker registration. */ > +extern int register_wss_receiver(void *receiver, struct pglist_data *pgdat, > + unsigned long *intervals, unsigned long nr_bins, > + unsigned long report_threshold, > + unsigned long refresh_threshold); > +extern void unregister_wss_receiver(void *receiver); > +extern bool working_set_request(struct pglist_data *pgdat); > + > enum virtio_balloon_vq { > VIRTIO_BALLOON_VQ_INFLATE, > VIRTIO_BALLOON_VQ_DEFLATE, > VIRTIO_BALLOON_VQ_STATS, > VIRTIO_BALLOON_VQ_FREE_PAGE, > VIRTIO_BALLOON_VQ_REPORTING, > + VIRTIO_BALLOON_VQ_WS, > + VIRTIO_BALLOON_VQ_NOTIFY, > VIRTIO_BALLOON_VQ_MAX > }; > > @@ -54,7 +65,8 @@ enum virtio_balloon_config_read { > > struct virtio_balloon { > struct virtio_device *vdev; > - struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq; > + struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq, > + *ws_vq, *notification_vq; > > /* Balloon's own wq for cpu-intensive work items */ > struct workqueue_struct *balloon_wq; > @@ -64,6 +76,8 @@ 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; > + struct work_struct update_balloon_ws_work; > + struct work_struct update_balloon_notification_work; > > /* Prevent updating balloon when it is being canceled. */ > spinlock_t stop_update_lock; > @@ -110,6 +124,10 @@ struct virtio_balloon { > /* Memory statistics */ > struct virtio_balloon_stat stats[VIRTIO_BALLOON_S_NR]; > > + /* A buffer to hold incoming notification from the host. */ > + unsigned int notification_size; > + void *notification_buf; > + > /* Shrinker to return free pages - VIRTIO_BALLOON_F_FREE_PAGE_HINT */ > struct shrinker shrinker; > > @@ -119,6 +137,10 @@ struct virtio_balloon { > /* Free page reporting device */ > struct virtqueue *reporting_vq; > struct page_reporting_dev_info pr_dev_info; > + > + /* Working Set reporting */ > + u32 ws_num_bins; > + struct virtio_balloon_ws *ws; > }; > > static const struct virtio_device_id id_table[] = { > @@ -301,6 +323,41 @@ static unsigned int leak_balloon(struct virtio_balloon *vb, size_t num) > return num_freed_pages; > } > > +/* 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->ws_num_bins; ++i) { > + vb->ws[i].tag = cpu_to_virtio16(vb->vdev, 0); > + vb->ws[i].node_id = cpu_to_virtio16(vb->vdev, -1); > + vb->ws[i].idle_age_ms = cpu_to_virtio64(vb->vdev, 0); > + vb->ws[i].memory_size_bytes[0] = cpu_to_virtio64(vb->vdev, -1); > + vb->ws[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) > +{ > + vb->ws[idx].tag = cpu_to_virtio16(vb->vdev, 0); > + vb->ws[idx].node_id = cpu_to_virtio16(vb->vdev, -1); > + vb->ws[idx].idle_age_ms = cpu_to_virtio64(vb->vdev, idle_age); > + vb->ws[idx].memory_size_bytes[0] = cpu_to_virtio64(vb->vdev, > + bytes_anon); > + vb->ws[idx].memory_size_bytes[1] = cpu_to_virtio64(vb->vdev, > + bytes_file); > +} > + > +static bool working_set_is_init(struct virtio_balloon *vb) > +{ > + if (vb->ws[0].idle_age_ms > 0) > + return true; > + return false; > +} > + > static inline void update_stat(struct virtio_balloon *vb, int idx, > u16 tag, u64 val) > { > @@ -386,6 +443,16 @@ static void stats_handle_request(struct virtio_balloon *vb) > virtqueue_kick(vq); > } > > +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 inline s64 towards_target(struct virtio_balloon *vb) > { > s64 target; > @@ -465,6 +532,130 @@ static void update_balloon_stats_func(struct work_struct *work) > stats_handle_request(vb); > } > > +static int virtio_balloon_register_wss_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; > + > + 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]; > + pgdat = NODE_DATA(NUMA_NO_NODE); > + err = register_wss_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 *wss_receiver, struct wss_bin *bins) > +{ > + u64 bytes_nr_file, bytes_nr_anon; > + struct virtio_balloon *vb = wss_receiver; > + int idx = 0; > + > + if (!mutex_trylock(&vb->balloon_lock)) > + return; > + for (; idx < vb->ws_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); > + } > + 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_ws_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); > + working_set_request(pgdat); > + } 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->ws_num_bins - 1); > + refresh_ms = *((__virtio64 *) buf); > + buf += sizeof(__virtio64); > + report_ms = *((__virtio64 *) buf); > + virtio_balloon_register_wss_receiver(vb, bin_intervals, vb->ws_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_ws_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->ws_vq, &unused)) > + ; > + sg_init_one(&sg_out, vb->ws, sizeof(struct virtio_balloon_ws) * vb->ws_num_bins); > + err = virtqueue_add_outbuf(vb->ws_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->ws_vq); > + } > +} > + > static void update_balloon_size_func(struct work_struct *work) > { > struct virtio_balloon *vb; > @@ -508,6 +699,10 @@ 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_WS] = NULL; > + names[VIRTIO_BALLOON_VQ_WS] = 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 +719,13 @@ static int init_vqs(struct virtio_balloon *vb) > callbacks[VIRTIO_BALLOON_VQ_REPORTING] = balloon_ack; > } > > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING)) { > + names[VIRTIO_BALLOON_VQ_WS] = "ws"; > + callbacks[VIRTIO_BALLOON_VQ_WS] = NULL; > + names[VIRTIO_BALLOON_VQ_NOTIFY] = "notify"; > + callbacks[VIRTIO_BALLOON_VQ_NOTIFY] = notification_receive; > + } > + > err = virtio_find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX, vqs, > callbacks, names, NULL); > if (err) > @@ -534,6 +736,7 @@ 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 +756,23 @@ static int init_vqs(struct virtio_balloon *vb) > virtqueue_kick(vb->stats_vq); > } > > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING)) { > + struct scatterlist sg; > + > + vb->ws_vq = vqs[VIRTIO_BALLOON_VQ_WS]; > + 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); > + } > + } > + > if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) > vb->free_page_vq = vqs[VIRTIO_BALLOON_VQ_FREE_PAGE]; > > @@ -878,6 +1098,8 @@ 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); > + INIT_WORK(&vb->update_balloon_ws_work, update_balloon_ws_func); > + INIT_WORK(&vb->update_balloon_notification_work, update_balloon_notification_func); > spin_lock_init(&vb->stop_update_lock); > mutex_init(&vb->balloon_lock); > init_waitqueue_head(&vb->acked); > @@ -885,6 +1107,20 @@ static int virtballoon_probe(struct virtio_device *vdev) > > balloon_devinfo_init(&vb->vb_dev_info); > > + if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_WS_REPORTING)) { > + virtio_cread_le(vdev, struct virtio_balloon_config, ws_num_bins, > + &vb->ws_num_bins); > + /* Allocate space for a Working Set report. */ > + vb->ws = kcalloc(vb->ws_num_bins, > + sizeof(struct virtio_balloon_ws), GFP_KERNEL); > + /* Allocate space for host notifications. */ > + vb->notification_size = > + sizeof(uint16_t) + > + sizeof(uint64_t) * (vb->ws_num_bins + 1); > + vb->notification_buf = kzalloc(vb->notification_size, GFP_KERNEL); > + reset_working_set(vb); > + } > + > err = init_vqs(vb); > if (err) > goto out_free_vb; > @@ -1034,11 +1270,15 @@ 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); > + if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_WS_REPORTING)) > + unregister_wss_receiver(vb); > 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); > + cancel_work_sync(&vb->update_balloon_ws_work); > + cancel_work_sync(&vb->update_balloon_notification_work); > > if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) { > cancel_work_sync(&vb->report_free_page_work); > @@ -1104,6 +1344,7 @@ 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 5ca2d5699620..2cf4fca6e7f1 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 +68,11 @@ 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); > +/* > + * Function to send the working set to a receiver (e.g. the balloon driver) > + * TODO: Replace with a proper registration interface, similar to shrinkers. > + */ > +extern void working_set_notify(void *wss_receiver, struct wss_bin *bins); > > static inline void balloon_devinfo_init(struct balloon_dev_info *balloon) > { > diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h > index ddaa45e723c4..06d0683d8d8c 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 +60,8 @@ 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. */ > + __le32 ws_num_bins; > }; > > #define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */ > @@ -116,4 +119,22 @@ struct virtio_balloon_stat { > __virtio64 val; > } __attribute__((packed)); > > +enum virtio_balloon_ws_op { > + VIRTIO_BALLOON_WS_REQUEST = 1, > + VIRTIO_BALLOON_WS_CONFIG = 2, > +}; > + > +struct virtio_balloon_ws { > +#define VIRTIO_BALLOON_WS_RECLAIMABLE 0 > +#define VIRTIO_BALLOON_WS_DISCARDABLE 1 > + /* TODO: Provide additional detail on memory, e.g. reclaimable. */ > + __virtio16 tag; > + /* TODO: Support per-NUMA node reports. */ > + __virtio16 node_id; > + uint8_t reserved[4]; > + __virtio64 idle_age_ms; > + /* Track separately for ANON_AND_FILE. */ > + __virtio64 memory_size_bytes[2]; > +}; > + > #endif /* _LINUX_VIRTIO_BALLOON_H */ > diff --git a/mm/vmscan.c b/mm/vmscan.c > index b3adf924691c..ab343974de91 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -209,6 +209,8 @@ static void set_task_reclaim_state(struct task_struct *task, > LIST_HEAD(shrinker_list); > DECLARE_RWSEM(shrinker_rwsem); > > +static void *wss_receiver; > + > #ifdef CONFIG_MEMCG > static int shrinker_nr_max; > > @@ -621,6 +623,54 @@ static unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, > return size; > } > > +/* > + * Register/unregister a receiver of wss notifications > + * TODO: Replace with a proper registration interface, similar to shrinkers. > + */ > +int register_wss_receiver(void *receiver, struct pglist_data *pgdat, > + unsigned long *intervals, unsigned long nr_bins, > + unsigned long refresh_threshold, > + unsigned long report_threshold) > +{ > + struct wss *wss; > + struct wss_bin *bins; > + int i; > + > + wss_receiver = receiver; > + > + if (!pgdat) > + return 0; > + > + if (!intervals || !nr_bins) > + return 0; > + > + bins = kzalloc(sizeof(wss->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; > + > + wss = lruvec_wss(mem_cgroup_lruvec(NULL, pgdat)); > + > + mutex_lock(&wss->bins_lock); > + memcpy(wss->bins, bins, sizeof(wss->bins)); > + WRITE_ONCE(wss->refresh_threshold, msecs_to_jiffies(refresh_threshold)); > + WRITE_ONCE(wss->report_threshold, msecs_to_jiffies(report_threshold)); > + mutex_unlock(&wss->bins_lock); > + return 0; > +} > +EXPORT_SYMBOL(register_wss_receiver); > + > +void unregister_wss_receiver(void *receiver) > +{ > + wss_receiver = NULL; > +} > +EXPORT_SYMBOL(unregister_wss_receiver); > + > /* > * Add a shrinker callback to be called from the vm. > */ > @@ -4606,6 +4656,12 @@ void report_wss(struct pglist_data *pgdat, struct scan_control *sc) > refresh_wss(wss, memcg, pgdat, sc, 0); > WRITE_ONCE(wss->timestamp, jiffies); > > + /* balloon driver subscribes to global memory reclaim */ > + if (!cgroup_reclaim(sc) && wss_receiver) { > + pr_warn("Working Set Notify!"); > + working_set_notify(wss_receiver, wss->bins); > + } > + > mutex_unlock(&wss->bins_lock); > > if (wss->notifier) > @@ -4711,6 +4767,52 @@ void report_reaccess(struct lruvec *lruvec, struct lru_gen_mm_walk *walk) > } > } > > +/* 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 wss *wss; > + > + if (!wss_receiver) > + return false; > + > + wss = lruvec_wss(mem_cgroup_lruvec(NULL, pgdat)); > + > + if (!mutex_trylock(&wss->bins_lock)) > + return false; > + > + if (wss->bins->idle_age != -1) { > + unsigned long timestamp = READ_ONCE(wss->timestamp); > + unsigned long threshold = READ_ONCE(wss->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_wss(wss, NULL, pgdat, &sc, threshold); > + memalloc_noreclaim_restore(flags); > + set_task_reclaim_state(current, NULL); > + } > + } > + > + if (wss_receiver) { > + pr_warn("WS notify inside ws request\n"); > + working_set_notify(wss_receiver, wss->bins); > + } > + > + mutex_unlock(&wss->bins_lock); > + return true; > + > +} > +EXPORT_SYMBOL(working_set_request); > + > static struct pglist_data *kobj_to_pgdat(struct kobject *kobj) > { > int nid = IS_ENABLED(CONFIG_NUMA) ? kobj_to_dev(kobj)->id : > -- > 2.40.1.521.gf1e218fcd8-goog >
