[PATCH v1] scsi: ufs: Fix imprecise time in devfreq window
From: Stanley Chu <hidden>
Date: 2020-06-09 15:33:41
Also in:
linux-mediatek, linux-scsi, lkml
Subsystem:
scsi subsystem, the rest · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds
Promise precision of devfreq windows by 1. Align time base of both devfreq_dev_status.total_time and devfreq_dev_status.busy_time to ktime-based time. 2. Align below timelines, - The beginning of devfreq window - The beginning of busy time in new window - The end of busy time in current window Signed-off-by: Stanley Chu <redacted> --- drivers/scsi/ufs/ufshcd.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ad4fc829cbb2..940bd5de5ade 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c@@ -1314,6 +1314,7 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, unsigned long flags; struct list_head *clk_list = &hba->clk_list_head; struct ufs_clk_info *clki; + ktime_t curr_t; if (!ufshcd_is_clkscaling_supported(hba)) return -EINVAL;
@@ -1321,6 +1322,7 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, memset(stat, 0, sizeof(*stat)); spin_lock_irqsave(hba->host->host_lock, flags); + curr_t = ktime_get(); if (!scaling->window_start_t) goto start_window;
@@ -1332,18 +1334,17 @@ static int ufshcd_devfreq_get_dev_status(struct device *dev, */ stat->current_frequency = clki->curr_freq; if (scaling->is_busy_started) - scaling->tot_busy_t += ktime_to_us(ktime_sub(ktime_get(), + scaling->tot_busy_t += ktime_to_us(ktime_sub(curr_t, scaling->busy_start_t)); - stat->total_time = jiffies_to_usecs((long)jiffies - - (long)scaling->window_start_t); + stat->total_time = ktime_to_us(curr_t) - scaling->window_start_t; stat->busy_time = scaling->tot_busy_t; start_window: - scaling->window_start_t = jiffies; + scaling->window_start_t = curr_t; scaling->tot_busy_t = 0; if (hba->outstanding_reqs) { - scaling->busy_start_t = ktime_get(); + scaling->busy_start_t = curr_t; scaling->is_busy_started = true; } else { scaling->busy_start_t = 0;
--
2.18.0
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