If no firmware is found on the system that matches the processor, the microcode module can take hours to load. For example on recent kernels when loading the microcode module on an Intel system:
[ 239.532116] microcode: CPU0 sig=0x306e4, pf=0x1, revision=0x413 [ 299.693447] microcode: CPU1 sig=0x306e4, pf=0x1, revision=0x413 [ 359.821972] microcode: CPU2 sig=0x306e4, pf=0x1, revision=0x413 [ 419.960263] microcode: CPU3 sig=0x306e4, pf=0x1, revision=0x413 [ 480.090024] microcode: CPU4 sig=0x306e4, pf=0x1, revision=0x413 ... [ 2825.151364] microcode: CPU43 sig=0x306e4, pf=0x1, revision=0x413 [ 2885.280863] microcode: CPU44 sig=0x306e4, pf=0x1, revision=0x413 [ 2945.410719] microcode: CPU45 sig=0x306e4, pf=0x1, revision=0x413 [ 3005.540541] microcode: CPU46 sig=0x306e4, pf=0x1, revision=0x413 [ 3065.670405] microcode: CPU47 sig=0x306e4, pf=0x1, revision=0x413 ... etc. Since this takes 1 minute per cpu, the microcode module requires two hours to load on a 120 cpu Intel box. Similarly there is a 60 second "hang" when loading the AMD module, which isn't as bad as the Intel situation, but it is a noticeable delay in the system boot. Using request_firmware_nowait() seems more appropriate here and then we can avoid these delays, resulting in very quick load times for the microcode. Signed-off-by: Prarit Bhargava <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Prarit Bhargava (2): firmware, fix request_firmware_nowait() freeze with no uevent intel_microcode, Fix long microcode load time when firmware file is missing arch/x86/include/asm/microcode.h | 7 ++++ arch/x86/kernel/microcode_amd.c | 79 +++++++++++++++++++++++++++---------- arch/x86/kernel/microcode_core.c | 7 ++++ arch/x86/kernel/microcode_intel.c | 67 +++++++++++++++++++++++++------ drivers/base/firmware_class.c | 6 ++- 5 files changed, 132 insertions(+), 34 deletions(-) -- 1.7.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
