Commit 540eb1ee authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Martin K. Petersen

scsi: libfc: fix seconds_since_last_reset calculation

The fc_get_host_stats() function contains a complex conversion from
jiffies to timespec to seconds. As we try to get rid of uses of struct
timespec, we can clean this up and replace it with a simpler

Simply dividing the difference in jiffies by HZ is not only much more
efficient, it also avoids a problem that causes the
seconds_since_last_reset value to be incorrect if jiffies has overrun
since the 'boot_time' value was recorded.
Signed-off-by: default avatarArnd Bergmann <>
Reviewed-by: default avatarBart Van Assche <>
Signed-off-by: default avatarMartin K. Petersen <>
parent 0da21c44
......@@ -301,7 +301,6 @@ struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
struct fc_host_statistics *fc_stats;
struct fc_lport *lport = shost_priv(shost);
struct timespec v0, v1;
unsigned int cpu;
u64 fcp_in_bytes = 0;
u64 fcp_out_bytes = 0;
......@@ -309,9 +308,7 @@ struct fc_host_statistics *fc_get_host_stats(struct Scsi_Host *shost)
fc_stats = &lport->host_stats;
memset(fc_stats, 0, sizeof(struct fc_host_statistics));
jiffies_to_timespec(jiffies, &v0);
jiffies_to_timespec(lport->boot_time, &v1);
fc_stats->seconds_since_last_reset = (v0.tv_sec - v1.tv_sec);
fc_stats->seconds_since_last_reset = (lport->boot_time - jiffies) / HZ;
for_each_possible_cpu(cpu) {
struct fc_stats *stats;
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