On 07/29/16 at 11:34am, Zhou Wenjian wrote:
> It will have a bad performance if the threads number is larger than
> the usable cpu number. So we should remind user of it.
>
> Signed-off-by: Zhou Wenjian <zhouwj-fnst at cn.fujitsu.com>
It makes sense to tell people who use option "-num-threads".
Ack it.
Acked-by: Baoquan He <bhe at redhat.com>
> ---
> makedumpfile.8 | 2 ++
> print_info.c | 2 ++
> 2 files changed, 4 insertions(+)
>
> diff --git a/makedumpfile.8 b/makedumpfile.8
> index 3b6f7e2..f74abea 100644
> --- a/makedumpfile.8
> +++ b/makedumpfile.8
> @@ -376,6 +376,8 @@ the kdump\-compressed format.
> \fB\-\-num\-threads\fR \fITHREADNUM\fR
> Using multiple threads to read and compress data of each page in parallel.
> And it will reduces time for saving \fIDUMPFILE\fR.
> +Note that if the usable cpu number is less than the thread number, it may
> +lead to great performance degradation.
> This feature only supports creating \fIDUMPFILE\fR in kdump\-comressed
> format from \fIVMCORE\fR in kdump\-compressed format or elf format.
> .br
> diff --git a/print_info.c b/print_info.c
> index 1a9f70c..2fbfb12 100644
> --- a/print_info.c
> +++ b/print_info.c
> @@ -200,6 +200,8 @@ print_usage(void)
> MSG(" [--num-threads THREADNUM]:\n");
> MSG(" Using multiple threads to read and compress data of each page in parallel.\n");
> MSG(" And it will reduces time for saving DUMPFILE.\n");
> + MSG(" Note that if the usable cpu number is less than the thread number, it may\n");
> + MSG(" lead to great performance degradation.\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("\n");
> --
> 1.8.3.1
>
>
>
