I get the following bug running 2.6.18 on malta34Kc . Freeing prom memory: 956kb freed Freeing firmware memory: 978944k freed Freeing unused kernel memory: 180k freed BUG: using smp_processor_id() in preemptible [00000000] code: swapper/1 caller is r4k_dma_cache_wback_inv+0x144/0x2a0 Call Trace: [<80117af8>] r4k_dma_cache_wback_inv+0x144/0x2a0 [<802e4b84>] debug_smp_processor_id+0xd4/0xf0 [<802e4b7c>] debug_smp_processor_id+0xcc/0xf0 ... CONFIG_DEBUG_PREEMPT is enabled. -- Bug cause is blast_dcache_range() in preemptible code [in r4k_dma_cache_wback_inv()]. blast_dcache_range() is constructed via __BUILD_BLAST_CACHE_RANGE that uses cpu_dcache_line_size(). It uses current_cpu_data that use smp_processor_id() in turn. In case of CONFIG_DEBUG_PREEMPT smp_processor_id emits BUG if we are executing with preemption enabled. Cpu options of cpu0 are assumed to be the superset of all processors. Can I make the same assumptions for cache line size and fix this issue the following way: Index: linux-2.6.18/include/asm-mips/cpu-features.h =================================================================== --- linux-2.6.18.orig/include/asm-mips/cpu-features.h +++ linux-2.6.18/include/asm-mips/cpu-features.h @@ -200,10 +200,10 @@ #endif #ifndef cpu_dcache_line_size -#define cpu_dcache_line_size() current_cpu_data.dcache.linesz +#define cpu_dcache_line_size() cpu_data[0].dcache.linesz #endif #ifndef cpu_icache_line_size -#define cpu_icache_line_size() current_cpu_data.icache.linesz +#define cpu_icache_line_size() cpu_data[0].icache.linesz #endif #ifndef cpu_scache_line_size #define cpu_scache_line_size() current_cpu_data.scache.linesz Any suggestions would be greatly appreciated. --- Thanks, Pavel
