On Wed, Feb 13, 2019 at 4:08 PM Sergey Senozhatsky <[email protected]> wrote: > > On (02/13/19 15:14), xiang xiao wrote: > > > > But how can I precisely control timestamp on/off per message > > through sysfs node? > > > > Hmm. I don't know how many kernel printk-s you have and how often > do you write to kmsg.
It depend on use case, but I plan to create a generic driver which could reuse by all rpmsg based remoteproc. This is the driver for upstream: https://github.com/thesofproject/linux/pull/177/commits/a0b7009fede5552dc98733f2996a8140bff62455 so we need more precisely control here. > I was thinking about something like this: > > echo 0 > /...printk.../time > dump buffer to /dev/kmsg > echo 1 > /...printk../time > Another problem is how to control sysfs node from driver code naturally, the concurrency and global side effect also need to address. > - If you would have several kernel printk-s in the meantime, then > those would not have timestamps, but you kinda can roughly guess > it > > write [1243] foo > /dev/kmsg > write [1244] foo > /dev/kmsg > << printk(bar) <timestamp ~[1244,1245]> > write [1245] foo > /dev/kmsg > > Maybe this won't suffice. > > -ss
