Hi Denys, On 02/10/2017 03:14 AM, Denys Fedoryshchenko wrote: > After years of using kexec and recent unpleasant experience with modern (supposed to be blazing fast to boot) hardware that need 5-10 minutes just to pass POST tests, > one question came up to me: > Is it possible anyhow to execute regular (not special "panic" one to capture crash data) kexec on panic to reduce reboot time? Generally, you don't want to do this, because various platform hardware might be in non-quiescent states (still doing DMA to random memory, etc.) and other nastiness that means you don't want to do more than the minimal amount in a kexec on panic (crash). We've seen no end of fun and games even with just regular crash dumps while hardware is busily writing to memory that it shouldn't be. An IOMMU helps, but isn't a cure-all. Jon.
