printk/nmi: increase the size of NMI buffer and make it configurable

Testing has shown that the backtrace sometimes does not fit into the 4kB
temporary buffer that is used in NMI context.  The warnings are gone
when I double the temporary buffer size.

This patch doubles the buffer size and makes it configurable.

Note that this problem existed even in the x86-specific implementation
that was added by the commit a9edc8809328 ("x86/nmi: Perform a safe NMI
stack trace on all CPUs").  Nobody noticed it because it did not print
any warnings.

Signed-off-by: Petr Mladek <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Russell King <[email protected]>
Cc: Daniel Thompson <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: David Miller <[email protected]>
Cc: Daniel Thompson <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions