On 10/24/2013 07:17 AM, Henrique de Moraes Holschuh wrote: > On Wed, 23 Oct 2013, Prarit Bhargava wrote: >> After all this I completely forgot the problem I'm trying to solve here. The >> issue is that with HOTPLUG & request_microcode_nowait(), if the microcode >> image >> is not found (that is the file is not found on disk), then EACH cpu waits 1 >> minute and it takes 2 hours for a 120 cpu box to load the microcode module. > > The proper fix seems to be teaching the concept of negative caching to the > microcode core/drivers, as it was pointed out elsewhere in the thread. > Negative caching should have a lifetime of "the current update-all-cores > request". >
Yes, I'm implementing v2 to do this already; caching the microcode is obvious. I was actually looking at the code to see if there was a reason that each processor needs to do a load request but cannot see one. I'm modifying the microcode driver to do this, as I said, in v2. > This would fix the absurd compound timeout delays, as on most systems it > will result in just one timeout (the first one). > > That first timeout can be fixed by the user if they disable the userspace > firmware loader helper. IMHO that might well be the best choice, as it is > already the way forward. The problem with that is I may have a configuration which depends on having the userspace firmware loader helper for a device, but not the processors so IMO it isn't a complete solution. I've also toyed with the idea that there should be a request_firmware_timeout() in which a timeout for HOTPLUG can be specified. P. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
