On 2018/4/3 14:04, Wen Yang wrote:
There would be so many same lines printed by frequent printk if one
disk went wrong, like,
[ 546.185242] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185258] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185280] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185307] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185334] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185364] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185390] sd 0:1:0:0: rejecting I/O to offline device
[ 546.185410] sd 0:1:0:0: rejecting I/O to offline device
For slow serial console, the frequent printk may be blocked for a
long time, and if any spin_lock has been acquired before the printk
like in scsi_request_fn, watchdog could be triggered.
Related disscussion can be found here,
https://bugzilla.kernel.org/show_bug.cgi?id=199003
And Petr brought the idea to throttle the frequent printk, it's
useless to print the same lines frequently after all.
v2: fix some typos
v3: limit the print only for the same device
Suggested-by: Petr Mladek<[email protected]>
Suggested-by: Sergey Senozhatsky<[email protected]>
Signed-off-by: Wen Yang<[email protected]>
Signed-off-by: Jiang Biao<[email protected]>
Signed-off-by: Tan Hu<[email protected]>
Reviewed-by: Bart Van Assche<[email protected]>
CC: BartVanAssche<[email protected]>
CC: Petr Mladek<[email protected]>
CC: Sergey Senozhatsky<[email protected]>
CC: Martin K. Petersen<[email protected]>
CC: "James E.J. Bottomley"<[email protected]>
CC: Tejun Heo<[email protected]>
CC: JasonYan<[email protected]>
In my machine it works fine.
Tested-by: Jason Yan <[email protected]>
