Hello, RFC A painful subject:
I just noticed that stock systemd (no systemd debugging enabled) on my x86 box write()-s during shutdown to devkmsg more than before, so old devkmsg ratelimits do not apply: $ sudo journalctl -n 40000 -f | grep "kernel: printk: systemd-shutdow" kernel: printk: systemd-shutdow: 35 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 31 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 35 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 36 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 36 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 36 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 36 output lines suppressed due to ratelimiting kernel: printk: systemd-shutdow: 35 output lines suppressed due to ratelimiting I know that there is a "kernel.printk_devkmsg" interface; do we expect every systemd-enabled distro to find that out and to tweak kernel.printk_devkmsg or shall we change the default devkmsg ratelimit instead? ===================================================================== Every time I reboot my systemd x86_64 box: kernel: printk: systemd-shutdow: 36 output lines suppressed due to ratelimiting Apparently, the default ratelimit - 10 messages max, 5 * HZ interval - is a bit too restrictive these days, can't help it; so increase it to "50 messages, same interval" (which is not awfully a lot). Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com> --- kernel/printk/printk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 84e54250840a..0ed54f90f208 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -998,7 +998,8 @@ static int devkmsg_open(struct inode *inode, struct file *file) if (!user) return -ENOMEM; - ratelimit_default_init(&user->rs); + ratelimit_state_init(&user->rs, DEFAULT_RATELIMIT_INTERVAL, + 5 * DEFAULT_RATELIMIT_BURST); ratelimit_set_flags(&user->rs, RATELIMIT_MSG_ON_RELEASE); mutex_init(&user->lock); -- 2.20.1