From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jay Lan Date: Tue, 31 Oct 2006 18:08:40 +0000 Subject: Re: [PATCH]send slave cpus to SAL slave loop on crash (IA64) Message-Id: <45479128.7050100@sgi.com> List-Id: References: <4546623D.5000105@engr.sgi.com> In-Reply-To: <4546623D.5000105@engr.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org Zou, Nanhai wrote: >> We do not rely on machine crash on CPU 0 any more. If the >> crashing CPU is not cpu 0 and the cpu 0 not being returned to >> the slave loop, this case is handled by our PROM now. >> >> However, if somebody tries to boot up a production kernel using '-le' >> option _after_ the kexec'ed kernel is up running, the third kernel >> would not boot unless we boot up the second kernel with cpu 0. I >> posted a question on "if running 'kexec -le' on a kexec'ed kdump >> kernel is legal" earlier and Vivek responded saying the scenario >> is not guranteed to work. So, i think we are fine here. > > Ok, so with this patch and the PROM fix, on a SN system, > 1. Kdump -> 2nd kernel works. > 2. Kdump -> 2nd kernel -> Kexec to third kernel will not work. > 3. Kexec -> 2nd Kernel -> Kexec -> 3rd kernel works? > 4. Kexec -> 2nd Kernel -> Kdump -> 3rd kernel works? > > I think if scenario 1, 3 and 4 works it will be ok. Scenario 2 is not so useful I guess. > The '-l' option caused a seg fault of kexec: [root@pogo1 boot]# /home/jlan/kexec -l /boot/efi/efi/redhat/vmlinuz-2.6.18-kdump --initrd=/boot/efi/efi/redhat/initrd-2.6.18-kdump --append="root=/dev/sdb6 rhgb irqpoll ro quite" Done with process_options kernel: 0x2000000000328010 kernel_size: 3503fec memory_range: crashk, idx=5, start018000000, end028000000 memory_range: Boot, idx=7, start07a280010, end07a280061 memory_range: MemoryMap, idx=9, start07a3f0010, end07a3f0611 build_mem_shdrs: ei_class=2, e_shnumF, e_shoffT509848 build_mem_shdrs: sizeof(e_shdr)r, e_shdr=0x6000000000014120 ready to load. type=0, build_mem_shdrs: ei_class=2, e_shnumF, e_shoffT509848 build_mem_shdrs: sizeof(e_shdr)r, e_shdr=0x6000000000014f30 elf_exec_load Invalid memory segment 0x4000000 - 0x498bfff Segmentation fault [root@pogo1 boot]# It is on my list but my priority is to make sure kdump work (on sysrq-c, INIT, MCA) and to ensure /proc/vmcore contains correct and needed information for SN. Thanks, - jay