Re: [PATCH] printk: Export struct log size and member offsets through vmcoreinfo

From: Kay Sievers
Date: Fri Jul 20 2012 - 05:23:37 EST

On Thu, Jul 19, 2012 at 4:08 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote:
> On Thu, Jul 19, 2012 at 09:57:36AM -0400, Vivek Goyal wrote:
>> On Thu, Jul 19, 2012 at 11:38:57AM +0200, Kay Sievers wrote:

>> > If we would swap the 5 + 3 bit field byte declaration, and add
>> > __packed, we can still not rely on the level to be consistently the
>> > lower 3 bits of the byte, right?
> I think I missed your point in last response. Are you saying that retain
> bit fields for flags and level, and add __packed() and that will make sure
> level bits are always lowest 3bits?

It was more a question, I don't know how reliable that would be.

> I am really not sure how that is going
> to work. Also if you want to add more fields to struct log down the line,
> it will be a problem to determine the offset of byte where level bits are
> stored.

I guess, we could make sure that it's always the lowest 3 bits of a
byte. But the question if that is safe to do at all still remains. :)

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at