Messages in this thread | | | Subject | Re: strange timestamp in dmesg | From | Andi Kleen <> | Date | Fri, 06 Jun 2008 15:49:26 +0200 |
| |
Andrew Morton <akpm@linux-foundation.org> writes:
>> supports DPO and FUA >> [ 9.801761] sd 1:0:1:0: [sdc] 143374744 512-byte hardware sectors (73408 MB) >> [ 9.673388] sd 1:0:1:0: [sdc] Write Protect is off >> [ 9.673395] sd 1:0:1:0: [sdc] Mode Sense: ab 00 10 08 >> [ 9.806210] sd 1:0:1:0: [sdc] Write cache: enabled, read cache: enabled, >> supports DPO and FUA >> [ 9.806220] sdc: sdc1 >> [ 9.682136] sd 1:0:1:0: [sdc] Attached SCSI disk >> [ 13.786405] SGI XFS with large block numbers, no debug enabled >> [ 13.633457] XFS mounting filesystem sdb2 >> [ 13.724345] Starting XFS recovery on filesystem: sdb2 (logdev: internal) >> [ 14.251356] Ending XFS recovery on filesystem: sdb2 (logdev: internal) >> [ 15.379298] XFS mounting filesystem sdc1 >> [ 15.468255] Starting XFS recovery on filesystem: sdc1 (logdev: internal) >> [ 14.514314] Ending XFS recovery on filesystem: sdc1 (logdev: internal) >> [ 14.767260] warning: `squid' uses 32-bit capabilities (legacy support in use) >> [ 17.589751] e1000: eth0: e1000_watchdog: NIC Link is Up 1000 Mbps Full >> Duplex, Flow Control: RX/TX >> > > whoa, that's weird. We've seen timestamps jump forward a single hop of > ~100000 seconds, but that's all over the place.
No it's expected since printk uses sched_clock() and sched clock is not synchronous between CPUs on systems without synchronized/invariant TSC (like Opteron) All sched_clock() users are expected to handle it.
I always advocated just always using jiffies for printk. The only drawback would be that it won't increase in interrupt off sections, but if you have one that is longer than a jiffie then you have enough other problems.
-Andi
| |