A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-09 13:49:24 -04:00
Code Issues Projects Releases Packages Wiki Activity

Merge "printk: Make the console flush configurable in hotplug path"

Browse source
This commit is contained in:
qctecmdr 2019-07-30 06:50:41 -07:00 • committed by Gerrit - the friendly Code Review server
commit f136543ed0
2 changed files with 18 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

10
init/Kconfig
View file

@ -608,6 +608,16 @@ config LOG_BUF_SHIFT
13 => 8 KB
12 => 4 KB
config CONSOLE_FLUSH_ON_HOTPLUG
bool "Enable console flush configurable in hot plug code path"
depends on HOTPLUG_CPU
def_bool n
help
In cpu hot plug path console lock acquire and release causes the
console to flush. If console lock is not free hot plug latency
increases. So make console flush configurable in hot plug path
and default disabled to help in cpu hot plug latencies.
config LOG_CPU_MAX_BUF_SHIFT
int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
depends on SMP

10
kernel/printk/printk.c
View file

@ -2245,6 +2245,8 @@ void resume_console(void)
console_unlock();
}
#ifdef CONFIG_CONSOLE_FLUSH_ON_HOTPLUG
/**
* console_cpu_notify - print deferred console messages after CPU hotplug
* @cpu: unused
@ -2264,6 +2266,8 @@ static int console_cpu_notify(unsigned int cpu)
return 0;
}
#endif
/**
* console_lock - lock the console system for exclusive use.
*
@ -2894,7 +2898,7 @@ void __init console_init(void)
static int __init printk_late_init(void)
{
struct console *con;
int ret;
int ret = 0;
for_each_console(con) {
if (!(con->flags & CON_BOOT))
@ -2916,13 +2920,15 @@ static int __init printk_late_init(void)
unregister_console(con);
}
}
#ifdef CONFIG_CONSOLE_FLUSH_ON_HOTPLUG
ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL,
console_cpu_notify);
WARN_ON(ret < 0);
ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
console_cpu_notify, NULL);
WARN_ON(ret < 0);
return 0;
#endif
return ret;
}
late_initcall(printk_late_init);