From c51af826cf062af3c49a99a05a33236d93c57e72 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Fri, 15 Mar 2013 12:25:41 -0700 Subject: [PATCH] Drivers: hv: balloon: Execute hot-add code in a separate context Execute the hot-add operation in a separate work context. This allows us to decouple the pressure reporting activity from the "hot-add" activity. Testing has shown that this makes the guest more responsive to hot add requests. Signed-off-by: K. Y. Srinivasan Reviewed-by: Haiyang Zhang Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_balloon.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index 8dc406c..13fda38 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -417,6 +417,11 @@ struct balloon_state { struct work_struct wrk; }; +struct hot_add_wrk { + union dm_mem_page_range ha_page_range; + struct work_struct wrk; +}; + static bool hot_add; static bool do_hot_add; /* @@ -469,6 +474,11 @@ struct hv_dynmem_device { struct balloon_state balloon_wrk; /* + * State to execute the "hot-add" operation. + */ + struct hot_add_wrk ha_wrk; + + /* * This thread handles hot-add * requests from the host as well as notifying * the host with regards to memory pressure in @@ -486,7 +496,7 @@ struct hv_dynmem_device { static struct hv_dynmem_device dm_device; -static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg) +static void hot_add_req(struct work_struct *dummy) { struct dm_hot_add_response resp; @@ -509,8 +519,8 @@ static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg) resp.page_count = 0; resp.result = 0; - dm->state = DM_INITIALIZED; - vmbus_sendpacket(dm->dev->channel, &resp, + dm_device.state = DM_INITIALIZED; + vmbus_sendpacket(dm_device.dev->channel, &resp, sizeof(struct dm_hot_add_response), (unsigned long)NULL, VM_PKT_DATA_INBAND, 0); @@ -771,7 +781,6 @@ static int dm_thread_func(void *dm_dev) { struct hv_dynmem_device *dm = dm_dev; int t; - unsigned long scan_start; while (!kthread_should_stop()) { t = wait_for_completion_timeout(&dm_device.config_event, 1*HZ); @@ -783,19 +792,6 @@ static int dm_thread_func(void *dm_dev) if (t == 0) post_status(dm); - scan_start = jiffies; - switch (dm->state) { - - case DM_HOT_ADD: - hot_add_req(dm, (struct dm_hot_add *)recv_buffer); - break; - default: - break; - } - - if (!time_in_range(jiffies, scan_start, scan_start + HZ)) - post_status(dm); - } return 0; @@ -869,6 +865,8 @@ static void balloon_onchannelcallback(void *context) struct dm_header *dm_hdr; struct hv_dynmem_device *dm = hv_get_drvdata(dev); struct dm_balloon *bal_msg; + struct dm_hot_add *ha_msg; + union dm_mem_page_range *ha_pg_range; memset(recv_buffer, 0, sizeof(recv_buffer)); vmbus_recvpacket(dev->channel, recv_buffer, @@ -905,8 +903,13 @@ static void balloon_onchannelcallback(void *context) break; case DM_MEM_HOT_ADD_REQUEST: + if (dm->state == DM_HOT_ADD) + pr_warn("Currently hot-adding\n"); dm->state = DM_HOT_ADD; - complete(&dm->config_event); + ha_msg = (struct dm_hot_add *)recv_buffer; + ha_pg_range = &ha_msg->range; + dm_device.ha_wrk.ha_page_range = *ha_pg_range; + schedule_work(&dm_device.ha_wrk.wrk); break; case DM_INFO_MESSAGE: @@ -950,6 +953,7 @@ static int balloon_probe(struct hv_device *dev, init_completion(&dm_device.host_event); init_completion(&dm_device.config_event); INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up); + INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req); dm_device.thread = kthread_run(dm_thread_func, &dm_device, "hv_balloon"); @@ -1062,6 +1066,7 @@ static int balloon_remove(struct hv_device *dev) pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned); cancel_work_sync(&dm->balloon_wrk.wrk); + cancel_work_sync(&dm->ha_wrk.wrk); vmbus_close(dev->channel); kthread_stop(dm->thread); kfree(send_buffer); -- 2.7.4