On (12/12/16 16:58), Petr Mladek wrote: > On Thu 2016-12-01 22:55:44, Sergey Senozhatsky wrote: [..] > But not really because we report lost messages from both buffers > and from all CPUs here. [..] > The perfect solution would be to remember the number of lost messages > in struct printk_safe_seq_buf. Then we might bump the value directly > in printk_safe_log_store() instead of returning the ugly -ENOSPC.
ok, I can take a look. this won't grow the per-CPU buffers bigger, but will shrink the actual message buffer size by sizeof(atomic), not that dramatic. * unrelated, can be done later (if ever) * speaking of tha actual message buffer size, we, may be, can move `struct irq_work' out of printk_safe_seq_buf. there is already a printk-related per-CPU irq_work in place - wake_up_klogd_work. so we may be can use it, instead of defining a bunch of new irq_works. this will increase the printk-safe/nmi per-CPU message buffer size by sizeof(irq_work). > Also we could use an universal message (no "NMI" or "printk-safe") > because it could be printed right after flushing the messages > that fit the buffer. this "context" part probably can be dropped. both printk-safe and printk-nmi per-CPU buffer sizes are controlled by a single .config option anyway; user can't increase the printk-safe buffer size without increasing the printk-nmi buffer size (in case if printk-safe buffer is too small). > This solution is good enough and still better than the previous one, so > > Reviewed-by: Petr Mladek <pmla...@suse.com> thanks. -ss