kernel_optimize_test/kernel/printk
John Ogness 896fbe20b4 printk: use the lockless ringbuffer
Replace the existing ringbuffer usage and implementation with
lockless ringbuffer usage. Even though the new ringbuffer does not
require locking, all existing locking is left in place. Therefore,
this change is purely replacing the underlining ringbuffer.

Changes that exist due to the ringbuffer replacement:

- The VMCOREINFO has been updated for the new structures.

- Dictionary data is now stored in a separate data buffer from the
  human-readable messages. The dictionary data buffer is set to the
  same size as the message buffer. Therefore, the total required
  memory for both dictionary and message data is
  2 * (2 ^ CONFIG_LOG_BUF_SHIFT) for the initial static buffers and
  2 * log_buf_len (the kernel parameter) for the dynamic buffers.

- Record meta-data is now stored in a separate array of descriptors.
  This is an additional 72 * (2 ^ (CONFIG_LOG_BUF_SHIFT - 5)) bytes
  for the static array and 72 * (log_buf_len >> 5) bytes for the
  dynamic array.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20200709132344.760-5-john.ogness@linutronix.de
2020-07-10 08:48:55 +02:00
..
braille.c printk: Replace strncmp() with str_has_prefix() 2019-08-16 09:54:08 +02:00
braille.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
console_cmdline.h printk: Fix preferred console selection with multiple matches 2020-02-18 09:34:42 +01:00
internal.h printk: Prepare for nested printk_nmi_enter() 2020-05-19 15:51:16 +02:00
Makefile printk: add lockless ringbuffer 2020-07-10 08:48:19 +02:00
printk_ringbuffer.c printk: add lockless ringbuffer 2020-07-10 08:48:19 +02:00
printk_ringbuffer.h printk: add lockless ringbuffer 2020-07-10 08:48:19 +02:00
printk_safe.c One more printk change for 5.8 2020-06-12 12:13:36 -07:00
printk.c printk: use the lockless ringbuffer 2020-07-10 08:48:55 +02:00