>From the test result, we can see when "-d 31" is specified, using "--num-threads" always spends more time than not. And it occurs at most of the time in theory. So it should be mentioned in the description of "--num-threads".
Signed-off-by: Zhou Wenjian <[email protected]> --- makedumpfile.8 | 6 ++++-- print_info.c | 4 ++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/makedumpfile.8 b/makedumpfile.8 index 6eff4f1..ec179a5 100644 --- a/makedumpfile.8 +++ b/makedumpfile.8 @@ -378,11 +378,13 @@ Using multiple threads to read and compress data of each page in parallel. And it will reduces time for saving \fIDUMPFILE\fR. This feature only supports creating \fIDUMPFILE\fR in kdump\-comressed format from \fIVMCORE\fR in kdump\-compressed format or elf format. +Note that if too many pages are filtered, \'\-\-num\-threads\' may not improve +the performance, or even has bad effects. It means if \'\-d 31\' is specified, +you should think about whether to use \'\-\-num\-threads\'. .br .B Example: .br -# makedumpfile \-d 31 \-\-num\-threads 4 /proc/vmcore dumpfile - +# makedumpfile \-\-num\-threads 4 /proc/vmcore dumpfile .TP \fB\-\-reassemble\fR Reassemble multiple \fIDUMPFILE\fRs, which are created by \-\-split option, diff --git a/print_info.c b/print_info.c index d662c0c..d0302a8 100644 --- a/print_info.c +++ b/print_info.c @@ -194,6 +194,10 @@ print_usage(void) MSG(" And it will reduces time for saving DUMPFILE.\n"); MSG(" This feature only supports creating DUMPFILE in kdump-comressed format from\n"); MSG(" VMCORE in kdump-compressed format or elf format.\n"); + MSG(" Note that if too many pages are filtered, '--num-threads' may not improve\n"); + MSG(" the performance, or even has bad effects.\n"); + MSG(" It means if '-d 31' is specified, you should think about whether to use\n"); + MSG(" '--num-threads'.\n"); MSG("\n"); MSG(" [--reassemble]:\n"); MSG(" Reassemble multiple DUMPFILEs, which are created by --split option,\n"); -- 1.8.3.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
