Message ID | 20180628025501.20676-1-stewart@linux.ibm.com |
---|---|
Headers | show |
Series | Faster fast reboot (2x!) | expand |
On Thu, 28 Jun 2018 12:54:55 +1000 Stewart Smith <stewart@linux.ibm.com> wrote: > Currently, on a 128GB p9dsu system (with all that memory on node0), it > takes around 13 seconds in skiboot to do a fast reboot. > > By doing the clear in parallel, we get this down to ~11seconds. > By then doing it in parallel with PCI scanning, we're down to ~9 > seconds. > By then caching BOOTKERNEL rather than re-reading it, we're down to > ~5seconds. Very nice result! All the patches and rationales seem reasonable to me. I can take another look at my patch and write a proper changelog for it if you want to merge it. Did you have to make any changes? Thanks, Nick > > With this patchset, we're down to the following big consumers of time: > - 2.5s decompressing initramfs in BOOTKERNEL > - the amazing amount of time it takes for a linux OS to get to the point > of issuing 'reboot' to firmware. > > Nicholas Piggin (1): > Add cpu_queue_job_on_node() to do node local jobs
Nicholas Piggin <npiggin@gmail.com> writes: > On Thu, 28 Jun 2018 12:54:55 +1000 > Stewart Smith <stewart@linux.ibm.com> wrote: > >> Currently, on a 128GB p9dsu system (with all that memory on node0), it >> takes around 13 seconds in skiboot to do a fast reboot. >> >> By doing the clear in parallel, we get this down to ~11seconds. >> By then doing it in parallel with PCI scanning, we're down to ~9 >> seconds. >> By then caching BOOTKERNEL rather than re-reading it, we're down to >> ~5seconds. > > Very nice result! All the patches and rationales seem reasonable to me. > > I can take another look at my patch and write a proper changelog for it > if you want to merge it. Did you have to make any changes? I think it all looks good now. I'm a bit umming and ahhing over if I want to pull in the pnor caching code now or modify it a bit to do some sanity checks before using the cache. I think I'll leave it for the time being though, force myself to do it correctly :)