Thanks for replying Baoquan. Our production kernel is 3.4 and it has legacy dmesg buffer. I was able to dump it from oldmem. If this change is of any use for community I could try submit the patch. On Fri, Apr 4, 2014 at 4:14 AM, Baoquan He <bhe at redhat.com> wrote: > On 03/14/14 at 10:39pm, Prasad Koya wrote: >> Hi >> >> I'm increasing dmesg buffer size at runtime by passing log_buf_len=1M >> (or 512K) at command line. At compile time, I have LOG_BUF_LEN as >> 256K. However, when this kernel crashes (crashkernel set at 64M), >> vmcore-dmesg fails with below error. >> >> No program header covering vaddr 0xffff88013ff00000found kexec bug? >> >> Am I missing something here? >> >> Thank you. >> >> Here are some debugs I added to kernel. This is with 3.4 kernel and >> I've tried with kexec-tools-2.0.4. >> >> [ 0.000000] log_buf_len_setup: log_buf_len 262144 new 1048576 >> ffffffff8170b140 >> [ 0.000000] setup_log_buf: early 1 262144 new_log_buf_len 1048576 >> [ 0.000000] log_buf_len: 1048576 ffff880037d58000 >> [ 0.000000] early log buf free: 258671(98%) >> [ 0.000000] setup_log_buf: early 0 1048576 new_log_buf_len 0 >> [ 0.503752] log_buf_kexec_setup: lbl 1048576 new 0 ffffffff816198c4 >> logbuf ffff880037d58000 >> In kdump, running vmcore_dmesg /proc/vmcore >> No program header covering vaddr 0xffff88013ff00000found kexec bug? > > Hi Prasad, > > Did you try the latest kernel and vmcore-dmesg? Mine is OK. Surely you > need apply below patch since it's not merged yet. > > Author: Lubomir Rintel <lkundrak at v3.sk> > Date: Wed Sep 18 14:21:43 2013 +0200 > > vmcore-dmesg: Understand >= v3.11-rc4 dmesg > > Symbol name changed with the following commit: > 62e32ac printk: rename struct log to struct printk_log > > Thanks > Baoquan > >> >> _______________________________________________ >> kexec mailing list >> kexec at lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/kexec
