On Wed, 22 Aug 2007 21:08:38 +0900 "Ken'ichi Ohmichi" <oomichi at mxs.nes.nec.co.jp> wrote: > > Hi Andrew, > > This patch set frees the restriction that makedumpfile users should > install a vmlinux file (including the debugging information) into > each system. > > makedumpfile command is the dump filtering feature for kdump. > It creates a small dumpfile by filtering unnecessary pages for the > analysis. To distinguish unnecessary pages, it needs a vmlinux file > including the debugging information. These days, the debugging package > becomes a huge file, and it is hard to install it into each system. > > To solve the problem, kdump developers discussed it at lkml and kexec-ml. > As the result, we reached the conclusion that necessary information > for dump filtering (called "vmcoreinfo") should be embedded into the > first kernel file and it should be accessed through /proc/vmcore > during the second kernel. > (http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.0/1806.html) > > Dan Aloni created the patch set for the above implementation. > (http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.1/1053.html) > > And I updated it for multi architectures and memory models. > (http://lists.infradead.org/pipermail/kexec/2007-August/000479.html) so... will this permit us to generate kdump files whcih don't have any pagecache or anonymous memory in them? > +void vmcoreinfo_append_str(const char *fmt, ...); This should have suitable __attribute__s so that the compiler can check its use. See many examples in include/linux/kernel.h, around line 120. > +/* vmcoreinfo stuff */ > +unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; > +u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; > +unsigned int vmcoreinfo_size = 0; Please always run scripts/checkpatch.pl against your diffs. > +unsigned int vmcoreinfo_max_size = sizeof(vmcoreinfo_data); unsigned int = size_t? Perhaps vmcoreinfo_max_size should have size_t type? > +void crash_save_vmcoreinfo(void) > +{ > + u32 *buf; > + > + if (!vmcoreinfo_size) > + return; > + > + vmcoreinfo_append_str("CRASHTIME=%d", xtime.tv_sec); open-coded access to xtime probably isn't appropriate here. Consider using get_seconds(). That might be more accurate on tickless kernels, too. > + buf = (u32 *)vmcoreinfo_note; > + > + buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, > + vmcoreinfo_size); > + > + final_note(buf); > +} > + > +} > + > +static int __init crash_save_vmcoreinfo_init(void) > +{ > + vmcoreinfo_append_str("OSRELEASE=%s\n", UTS_RELEASE); > + vmcoreinfo_append_str("PAGESIZE=%d\n", PAGE_SIZE); I expect the virtualisation guys would be bothered by an open-coded access to UTS_RELEASE. I guess it doesn't matter much here, but perhaps it'd be setting a better example to use init_uts_ns.name.release?
