Messages in this thread Patch in this message | | | Date | Sun, 9 Jul 2000 15:51:34 -0400 | From | willy@thepuffi ... | Subject | CONFIG_SMP_CPUS |
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we have a lot of arrays which are declared as being NR_CPUS elements large. this is clearly suboptimal on the majority of SMP machines which have only 2 CPUs. i therefore believe this should be a config option. what do you think to this patch?
willy@femmeviolet:~/kernels/linux-2.4.0-t3p7$ ls -l vmlinux -rwxr-xr-x 1 willy willy 2622108 Jul 9 16:50 vmlinux (before, NR_CPUS = 32)
willy@femmeviolet:~/kernels/linux-willy$ ls -l vmlinux -rwxr-xr-x 1 willy willy 2572764 Jul 9 16:50 vmlinux (after, NR_CPUS = 2)
I think having 50k back is worthwhile, don't you?
diff -urNX exclude linux-2.4.0-t3p7/arch/i386/config.in linux-willy/arch/i386/config.in --- linux-2.4.0-t3p7/arch/i386/config.in Sun Jul 9 13:01:31 2000 +++ linux-willy/arch/i386/config.in Sun Jul 9 16:19:47 2000 @@ -139,6 +139,9 @@ define_bool CONFIG_X86_IO_APIC y define_bool CONFIG_X86_LOCAL_APIC y fi + define_int CONFIG_SMP_CPUS 1 +else + int 'Maximum number of CPUs to support (1-32)' CONFIG_SMP_CPUS 2 fi if [ "$CONFIG_SMP" = "y" -a "$CONFIG_X86_CMPXCHG" = "y" ]; then define_bool CONFIG_HAVE_DEC_LOCK y diff -urNX exclude linux-2.4.0-t3p7/include/linux/threads.h linux-willy/include/linux/threads.h --- linux-2.4.0-t3p7/include/linux/threads.h Wed May 24 22:52:41 2000 +++ linux-willy/include/linux/threads.h Sun Jul 9 16:20:19 2000 @@ -8,11 +8,7 @@ * /proc/sys/kernel/max-threads. */ -#ifdef CONFIG_SMP -#define NR_CPUS 32 /* Max processors that can be running in SMP */ -#else -#define NR_CPUS 1 -#endif +#define NR_CPUS CONFIG_SMP_CPUS /* Max processors that can be running in SMP */ #define MIN_THREADS_LEFT_FOR_ROOT 4
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