Re: linux-next: build failure after merge of the akpm-current tree

Luis R. Rodriguez
2014-06-26T08:29:42Z

On Thu, Jun 26, 2014 at 04:22:57PM +1000, Stephen Rothwell wrote:
> Hi Andrew,
>
> After merging the akpm tree, today's linux-next build (powerpc
> ppc44x_defconfig) failed like this:
>
> kernel/printk/printk.c: In function 'log_buf_add_cpu':
> kernel/printk/printk.c:269:37: error: 'CONFIG_LOG_CPU_MAX_BUF_SHIFT' undeclared (first use in this function)
> #define __LOG_CPU_MAX_BUF_LEN (1 << CONFIG_LOG_CPU_MAX_BUF_SHIFT)
> ^
> kernel/printk/printk.c:864:42: note: in expansion of macro '__LOG_CPU_MAX_BUF_LEN'
> cpu_extra = (num_possible_cpus() - 1) * __LOG_CPU_MAX_BUF_LEN;
> ^
> kernel/printk/printk.c:269:37: note: each undeclared identifier is reported only once for each function it appears in
> #define __LOG_CPU_MAX_BUF_LEN (1 << CONFIG_LOG_CPU_MAX_BUF_SHIFT)
> ^
> kernel/printk/printk.c:864:42: note: in expansion of macro '__LOG_CPU_MAX_BUF_LEN'
> cpu_extra = (num_possible_cpus() - 1) * __LOG_CPU_MAX_BUF_LEN;
> ^
>
> Caused by commit 58209adf633e ("printk: allow increasing the ring
> buffer depending on the number of CPUs"). CONFIG_LOG_CPU_MAX_BUF_SHIFT
> is not defined for this configuration.

diff --git a/init/Kconfig b/init/Kconfig
index 573d3f6..2339118 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -822,10 +822,9 @@ config LOG_BUF_SHIFT

config LOG_CPU_MAX_BUF_SHIFT
int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
- range 0 21
- default 12
- depends on SMP
- depends on !BASE_SMALL
+ range 0 21 if SMP && !BASE_SMALL
+ default 12 if SMP && !BASE_SMALL
+ default 0 if !SMP || BASE_SMALL
help
The kernel ring buffer will get additional data logged onto it
when multiple CPUs are supported. Typically the contributions are