[PATCH next v4 0/2] printk: remove logbuf_lock writer-protection of ringbuffer

[John Ogness]

Hello,

Here is a v4 of the series to partially remove logbuf_lock.
v3 is here[0]. This series removes logbuf_lock usage of most
ringbuffer writers. The remaining logbuf_lock users are
using the lock to synchronize other variables. These other
users will be addressed in a later series.

I have tried to keep these changes minimal so that we can feel
comfortable for the upcoming 5.11 merge window.

Although small, this series is significant because it allows
printk callers direct lockless access to the ringbuffer and
it replaces the use of a static sprint buffer with sprint'ing
directly to the reserved ringbuffer data block.

This series is based on next-20201208.

John Ogness

[0] https://lkml.kernel.org/r/20201207222020.2923-1-john.ogness@xxxxxxxxxxxxx

John Ogness (2):
  printk: inline log_output(),log_store() in vprintk_store()
  printk: remove logbuf_lock writer-protection of ringbuffer

 kernel/printk/printk.c | 247 ++++++++++++++++++++++++-----------------
 1 file changed, 147 insertions(+), 100 deletions(-)

-- 
2.20.1