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SubjectRe: [PATCH A+B] pmem: Add prints at module load and unload
On 04/13/2015 12:05 PM, Greg KH wrote:
> On Tue, Apr 07, 2015 at 06:46:15PM +0300, Boaz Harrosh wrote:
>> Hi Christoph, Ingo
>> It is important in the lab for postmortem analysis to know if
>> pmem driver loaded and/or unloaded. And the return code from this
>> operation.
>> I submit two versions [A] more chatty and version [B]. Both give me
>> the info I need.
>> I like [B] because [A] prints more lines, and also the driver might not
>> load at the end and we would still not see it from [A]'s prints.
>> But it does not matter that much just take any one you guys like
>> better.
>> Here are the commit logs:
>> ---
>> [PATCH 1A] pmem: Add prints at pmem_probe/remove
>> Add small prints at creation/remove of pmem devices.
>> So we can see in dmesg logs when users loaded/unloaded
>> the pmem driver and what devices were created.
>> The prints will look like this:
>> Printed by e820 on load:
>> [ +0.000000] user: [mem 0x0000000100000000-0x000000015fffffff] persistent (type 12)
>> [ +0.000000] user: [mem 0x0000000160000000-0x00000001dfffffff] persistent (type 12)
>> ...
>> Printed by modprobe pmem:
>> [ +0.003065] pmem probe [0x0000000100000000:0x60000000]
>> [ +0.001816] pmem probe [0x0000000160000000:0x80000000]
>> ...
>> Printed by modprobe -r pmem:
>> [ +16.299145] pmem remove
>> [ +0.011155] pmem remove
>> Signed-off-by: Boaz Harrosh <>
> Don't polute the kernel logs with "chatty" things like this,

Why do you say this is chatty. With [B] This is a single line of print
on modprobe. With [A] it is a print per device (Is why I like [B])
Compare to all the other block-devices in the system, say scsi, that print
bunch of info for each device, this is very very minimalistic.

> just
> trigger off of the block device uevent if you really want to know if the
> block device is still around or not.

Again I do not need this for run time. At run time I have two tons of ways
to check and see. BTW a uevent is already triggered for insertion as part
of regular block core operation.

I need this at dmesg for when analyzing users logs, say when a crash happens.
I need to see what/when drivers were loaded/unloaded. It is common practice
in dmseg for block devices to leave foot prints.

Sigh, do you not believe that this single line in dmseg makes my life much

> thanks,
> greg k-h


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