Re: [PATCH 0/2] printk: replace ringbuffer

[lijiang <lijiang@redhat.com>]

在 2020年01月29日 00:19, John Ogness 写道:
> Hello,
> 
> After several RFC series [0][1][2][3][4], here is the first set of
> patches to rework the printk subsystem. This first set of patches
> only replace the existing ringbuffer implementation. No locking is
> removed. No semantics/behavior of printk are changed.
> 
> The VMCOREINFO is updated, which will require changes to the
> external crash [5] tool. I will be preparing a patch to add support
> for the new VMCOREINFO.
> 
In addition to changing the crash utility, I would think that the
kexec-tools(such as the vmcore-dmesg and makedumpfile) also need to
be modified accordingly.

Thanks
Lianbo

> This series is in line with the agreements [6] made at the meeting
> during LPC2019 in Lisbon, with 1 exception: support for dictionaries
> will _not_ be discontinued [7]. Dictionaries are stored in a separate
> buffer so that they cannot interfere with the human-readable buffer.
> 
> John Ogness
> 
> [0] https://lkml.kernel.org/r/20190212143003.48446-1-john.ogness@linutronix.de
> [1] https://lkml.kernel.org/r/20190607162349.18199-1-john.ogness@linutronix.de
> [2] https://lkml.kernel.org/r/20190727013333.11260-1-john.ogness@linutronix.de
> [3] https://lkml.kernel.org/r/20190807222634.1723-1-john.ogness@linutronix.de
> [4] https://lkml.kernel.org/r/20191128015235.12940-1-john.ogness@linutronix.de
> [5] https://github.com/crash-utility/crash
> [6] https://lkml.kernel.org/r/87k1acz5rx.fsf@linutronix.de
> [7] https://lkml.kernel.org/r/20191007120134.ciywr3wale4gxa6v@pathway.suse.cz
> 
> John Ogness (2):
>   printk: add lockless buffer
>   printk: use the lockless ringbuffer
> 
>  include/linux/kmsg_dump.h         |    2 -
>  kernel/printk/Makefile            |    1 +
>  kernel/printk/printk.c            |  836 +++++++++---------
>  kernel/printk/printk_ringbuffer.c | 1370 +++++++++++++++++++++++++++++
>  kernel/printk/printk_ringbuffer.h |  328 +++++++
>  5 files changed, 2114 insertions(+), 423 deletions(-)
>  create mode 100644 kernel/printk/printk_ringbuffer.c
>  create mode 100644 kernel/printk/printk_ringbuffer.h
>