On Tue, Nov 15, 2016 at 02:50:17PM +0000, Bart Van Assche wrote: > On Tue, 2016-11-15 at 10:18 +0100, Johannes Thumshirn wrote: > > On Tue, Nov 08, 2016 at 03:04:43PM +0000, Bart Van Assche wrote: > > > I think the above code will miscalculate seconds_since_last_reset > > > if > > > 'jiffies' wraps around after an lport has been created and before > > > seconds_since_last_reset is computed. Shouldn't > > > seconds_since_last_reset > > > be computed as follows? > > > > > > fc_stats->seconds_since_last_reset = (jiffies - boot_time) / > > > HZ; > > > > But what happens when jiffies - boot_time becomes negative? Then we > > reintroduce the bug again and have 'fcoeadm -s' show weird values. > > Hello Johannes, > > If your concern is about 'jiffies' wrapping around on 32-bit systems > then you should use get_jiffies_64(). get_jiffies_64() - boot_time > can't become negative. It namely takes several million years before a > 64-bit HZ counter wraps around. You're right. I'll respin using get_jiffies_64() and resent once it is tested. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@xxxxxxx +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
