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Diffstat (limited to 'Documentation/kdump/kdump.txt')
| -rw-r--r-- | Documentation/kdump/kdump.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 88ff63d5fde3..b0eb27b956d9 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt @@ -393,6 +393,15 @@ Notes on loading the dump-capture kernel: * We generally don' have to bring up a SMP kernel just to capture the dump. Hence generally it is useful either to build a UP dump-capture kernel or specify maxcpus=1 option while loading dump-capture kernel. + Note, though maxcpus always works, you had better replace it with + nr_cpus to save memory if supported by the current ARCH, such as x86. + +* You should enable multi-cpu support in dump-capture kernel if you intend + to use multi-thread programs with it, such as parallel dump feature of + makedumpfile. Otherwise, the multi-thread program may have a great + performance degradation. To enable multi-cpu support, you should bring up an + SMP dump-capture kernel and specify maxcpus/nr_cpus, disable_cpu_apicid=[X] + options while loading it. * For s390x there are two kdump modes: If a ELF header is specified with the elfcorehdr= kernel parameter, it is used by the kdump kernel as it |