Hello Baoquan, >Hi Atsushi, > >I have got the test machine where bug reported and did a test. The >changed code can make elf dump successful. Great, thanks for your help! However, I still have questions. First, what is the difference between yours and mine? http://lists.infradead.org/pipermail/kexec/2014-April/011535.html My patch includes renaming some values, but the purpose looks the same as yours. Further, you described as below, >On 04/14/14 at 04:02pm, Baoquan He wrote: >> In case elf dump, the code to calculate the cyclic buffer size is >> not correct. Since elf need bitmap1/2, so the needed memory for >> bufsize_cyclic need be double. Hence free size should be 40% of >> free memory, however the needed_size which free_size is compared >> with should be info->max_mapnr / BITPERBYTE, but not 2 times of it. >> >> Because of this, in case of free memory in 2nd kernel is not too much, >> OOM will happen very often. but I still don't think this bug causes OOM. Even if needed_size is calculated as so much size wrongly, bufsize_cyclic will not exceed 40% of free memory by the check below: info->bufsize_cyclic = (free_size <= needed_size) ? free_size : needed_size; So it looks that bitmap1(40%) and bitmap2(40%) will fit in 80% of free memory in any case. I may misunderstand something since your patch has an effect on this issue in practice, could you correct me? Thanks Atsushi Kumagai >> Signed-off-by: Baoquan He <bhe at redhat.com> >> --- >> makedumpfile.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/makedumpfile.c b/makedumpfile.c >> index 75092a8..01ec516 100644 >> --- a/makedumpfile.c >> +++ b/makedumpfile.c >> @@ -9010,7 +9010,7 @@ calculate_cyclic_buffer_size(void) { >> */ >> if (info->flag_elf_dumpfile) { >> free_size = get_free_memory_size() * 0.4; >> - needed_size = (info->max_mapnr * 2) / BITPERBYTE; >> + needed_size = info->max_mapnr / BITPERBYTE; >> } else { >> free_size = get_free_memory_size() * 0.8; >> needed_size = info->max_mapnr / BITPERBYTE; >> -- >> 1.8.5.3 >> >> >> _______________________________________________ >> kexec mailing list >> kexec at lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/kexec
