[patch] Avoid duplicate string allocations for the same cpu type If a system has more than one cpu type, get_model_name() will allocate a unique "model name" string for each cpu different than the boot cpu. (See "model name" in /proc/cpuinfo for an example.) What compounds this is Intel's decision to give different steppings different model names. Montecito C1 is "Dual-Core Intel(R) Itanium(R) 2 Processor 9040" while Montecito C2 is "Dual-Core Intel(R) Itanium(R) 2 Processor 9050". That increases the likelyhood of having different cpu types. Model names are also getting longer, such as "Intel(r) Itanium(r) 2 Processor 1.6GHz with 18M L3 Cache for 533MHz Platforms". Each thread is treated as a different "cpu", further compounding the problem. This patch makes get_model_name() smarter. It allocates one string for each unique "model name" and returns a pointer to the appropriate string. It handles up to 8 different cpu types. Above that number it reverts to the previous behavior of allocating a unque string for each thread. Since all threads in a socket have the same "model name", there needs to be more than 8 different socket types to revert to the old behavior. Signed-off-by: Russ Anderson (rja@xxxxxxx) --- arch/ia64/kernel/setup.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) Index: test/arch/ia64/kernel/setup.c =================================================================== --- test.orig/arch/ia64/kernel/setup.c 2007-03-09 17:32:27.000000000 -0600 +++ test/arch/ia64/kernel/setup.c 2007-03-10 16:06:04.313548208 -0600 @@ -665,11 +665,14 @@ struct seq_operations cpuinfo_op = { }; static char brandname[128]; +#define BRAND_SIZE 8 +static char * brands[BRAND_SIZE]; static char * __cpuinit get_model_name(__u8 family, __u8 model) { char brand[128]; + int i; memcpy(brand, "Unknown", 8); if (ia64_pal_get_brand_info(brand)) { @@ -681,12 +684,24 @@ get_model_name(__u8 family, __u8 model) case 2: memcpy(brand, "Madison up to 9M cache", 23); break; } } - if (brandname[0] == '\0') - return strcpy(brandname, brand); - else if (strcmp(brandname, brand) == 0) - return brandname; - else - return kstrdup(brand, GFP_KERNEL); + /* + * kstrdup() cannot be called early in the boot process, + * so use a static buffer for the first cpu. + */ + if (!brands[0]) { + strcpy(brandname, brand); + brands[0] = brandname; + return brands[0]; + } + for (i = 0; i < BRAND_SIZE; i++) { + if (!brands[i]) { + brands[i] = kstrdup(brand, GFP_KERNEL); + return brands[i]; + } else if (strcmp(brands[i], brand) == 0) { + return brands[i]; + } + } + return kstrdup(brand, GFP_KERNEL); } static void __cpuinit -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@xxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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