Hi, 2007/03/23 09:26:02 +0900, "Ken'ichi Ohmichi" <oomichi@xxxxxxxxxxxxxxxxx> wrote: >>> 1) Makedumpfile patch: Ken'ichi Ohmichi's email of Wed, 7 Mar 2007 >>> 10:43:38 +0900 contained the patch "point_same_zero_page.patch". That >>> patch contains the nice solution to remove redundant zero page images >>> from the diskdump dump file by pointing the page descriptors of zero >>> pages to a common zero image. I suggest that this patch should be >>> applied to makedumpfile as soon as possible, without waiting on a >>> possible solution to the ELF situation. As described in my report, ELF >>> and diskdump dump files have not shown identical behavior in the past. >>> This patch makes diskdump dump files more accurate, and leaves ELF dump >>> files at the same level of accuracy that they have always had. > >I agree with Bob, I will merge the patch "point_same_zero_page.patch" into >a new makedumpfile. But this change is very important, and I want to check >that this change is correct by doing many tests. >I will release a new makedumpfile until the next weekend. I checked whether this change is correct by the following: (The following patches are attached with this mail) - makedumpfile-1.1.2 with "point_same_zero_page2.patch" creates a dumpfile. - crash-4.0-3.21 with "not-access-excluded-page.patch" analyzes the dumpfile. - The analysis result of the dumpfile is compared with /proc/vmcore's. And on i386 linux-2.6.19, I found the difference between the result of the dumpfile (excluding free pages) and /proc/vmcore's by subcommand "foreach bt". But by using crash-4.0-3.21 without "not-access-excluded-page.patch", there is not any difference. In a word, this difference happens due to considering the excluded pages as unaccess pages. It is the diff result of /proc/vmcore's analysis result and the dumpfile's as follows: --- result-vmcore.txt 2007-03-28 14:01:20.000000000 +0900 +++ result-dumpfile-d16.txt 2007-03-28 14:01:06.000000000 +0900 @@ -1,7 +1,24 @@ crash> foreach bt PID: 0 TASK: c037c440 CPU: 0 COMMAND: "swapper" +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b2a0) excluded from dump +bt: diskdump: paddr(44b2a0) excluded from dump +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b2a1) excluded from dump +bt: diskdump: paddr(44b2a1) excluded from dump +bt: cannot resolve stack trace: +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b1ae) excluded from dump +bt: diskdump: paddr(44b2a1) excluded from dump +bt: diskdump: paddr(44b2a1) excluded from dump #0 [c0446f54] schedule at c0311ef0 - #1 [c0446fcc] cpu_idle at c0102c8d +bt: text symbols on stack: + [c0446fb0] mwait_idle_with_hints at c0102235 + [c0446fcc] cpu_idle at c0102c92 + [c0446fd4] start_kernel at c044b56f + [c0446fdc] unknown_bootoption at c044b577 PID: 0 TASK: c812f050 CPU: 1 COMMAND: "swapper" #0 [c8127f3c] schedule at c0311ef0 _ The physical address 0x44b1ae is the symbol start_kernel's. The text start_kernel is freed at free_initmem() while the kernel booting, and it is not problem that this text is excluded as free pages. I did not research the detail of this problem. I guess that the crash utility expect it can read the text of each process. I think it is necessary not only the change of handling the excluded pages but also other changes of the crash utility. Thanks Ken'ihci Ohmichi
Attachment:
not-access-excluded-page.patch
Description: Binary data
Attachment:
point_same_zero_page2.patch
Description: Binary data
-- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
