Messages in this thread |  | | From | Sergey Senozhatsky <> | Subject | [RFC][PATCHv2 0/8] printk: introduce printing kernel thread | Date | Wed, 29 Mar 2017 18:25:03 +0900 |
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Hello
RFC
This patch set adds a printk() kernel thread which lets us to print kernel messages to the console from a non-atomic/schedule-able context, avoiding different sort of lockups, stalls, etc.
The biggest difference compared to v1 is a further expansion of "switch to old printk() mode", which we now call printk_emergency mode, annotations (pm, kexec, sysrq).
We also have a bunch of other ideas to try out/consider (not in this patch set). E.g. automatic printk_emergency switch on printk_kthread stalls (when we can't run printk_kthread), moving klogd irq_work out of per-CPU memory, and so on.
v1->v2: -- introduce printk_emergency mode and API to switch it on/off -- move printk_pending out of per-CPU memory -- add printk emergency_mode sysfs node -- switch sysrq handlers (some of them) to printk_emergency -- cleanus/etc.
Sergey Senozhatsky (8): printk: move printk_pending out of per-cpu printk: introduce printing kernel thread printk: offload printing from wake_up_klogd_work_func() pm: switch to printk.emergency mode in unsafe places sysrq: switch to printk.emergency mode in unsafe places kexec: switch to printk.emergency mode in unsafe places printk: add printk emergency_mode parameter printk: enable printk offloading
drivers/tty/sysrq.c | 7 ++ include/linux/console.h | 3 + kernel/kexec_core.c | 4 ++ kernel/power/hibernate.c | 8 +++ kernel/power/suspend.c | 4 ++ kernel/printk/printk.c | 178 +++++++++++++++++++++++++++++++++++++++++------ 6 files changed, 182 insertions(+), 22 deletions(-)
-- 2.12.2
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