On 1/2/19 3:00 PM, Daniel Jordan wrote:
On Sun, Dec 30, 2018 at 12:49:34PM +0800, Yang Shi wrote:
The test on my virtual machine with congested HDD shows long tail
latency is reduced significantly.
Without the patch
page_fault1_thr-1490 [023] 129.311706: funcgraph_entry: #57377.796 us | do_swap_page();
page_fault1_thr-1490 [023] 129.369103: funcgraph_entry: 5.642us | do_swap_page();
page_fault1_thr-1490 [023] 129.369119: funcgraph_entry: #1289.592 us | do_swap_page();
page_fault1_thr-1490 [023] 129.370411: funcgraph_entry: 4.957us | do_swap_page();
page_fault1_thr-1490 [023] 129.370419: funcgraph_entry: 1.940us | do_swap_page();
page_fault1_thr-1490 [023] 129.378847: funcgraph_entry: #1411.385 us | do_swap_page();
page_fault1_thr-1490 [023] 129.380262: funcgraph_entry: 3.916us | do_swap_page();
page_fault1_thr-1490 [023] 129.380275: funcgraph_entry: #4287.751 us | do_swap_page();
With the patch
runtest.py-1417 [020] 301.925911: funcgraph_entry: #9870.146 us | do_swap_page();
runtest.py-1417 [020] 301.935785: funcgraph_entry: 9.802us | do_swap_page();
runtest.py-1417 [020] 301.935799: funcgraph_entry: 3.551us | do_swap_page();
runtest.py-1417 [020] 301.935806: funcgraph_entry: 2.142us | do_swap_page();
runtest.py-1417 [020] 301.935853: funcgraph_entry: 6.938us | do_swap_page();
runtest.py-1417 [020] 301.935864: funcgraph_entry: 3.765us | do_swap_page();
runtest.py-1417 [020] 301.935871: funcgraph_entry: 3.600us | do_swap_page();
runtest.py-1417 [020] 301.935878: funcgraph_entry: 7.202us | do_swap_page();
Hi Yang, I guess runtest.py just calls page_fault1_thr? Being explicit about
Yes, runtest.py is the wrapper script of will-it-scale.
this may improve the changelog for those unfamiliar with will-it-scale.
Sure.
May also be useful to name will-it-scale and how it was run (#thr, runtime,
system cpus/memory/swap) for more context.
How about the below description:
The test with page_fault1 of will-it-scale (sometimes tracing may just
show runtest.py that is the wrapper script of page_fault1), which
basically launches NR_CPU threads to generate 128MB anonymous pages for
each thread, on my virtual machine with congested HDD shows long tail
latency is reduced significantly.
Without the patch
page_fault1_thr-1490 [023] 129.311706: funcgraph_entry: #57377.796
us | do_swap_page();
page_fault1_thr-1490 [023] 129.369103: funcgraph_entry: 5.642us
| do_swap_page();
page_fault1_thr-1490 [023] 129.369119: funcgraph_entry: #1289.592
us | do_swap_page();
page_fault1_thr-1490 [023] 129.370411: funcgraph_entry: 4.957us
| do_swap_page();
page_fault1_thr-1490 [023] 129.370419: funcgraph_entry: 1.940us
| do_swap_page();
page_fault1_thr-1490 [023] 129.378847: funcgraph_entry: #1411.385
us | do_swap_page();
page_fault1_thr-1490 [023] 129.380262: funcgraph_entry: 3.916us
| do_swap_page();
page_fault1_thr-1490 [023] 129.380275: funcgraph_entry: #4287.751
us | do_swap_page();
With the patch
runtest.py-1417 [020] 301.925911: funcgraph_entry: #9870.146
us | do_swap_page();
runtest.py-1417 [020] 301.935785: funcgraph_entry: 9.802us
| do_swap_page();
runtest.py-1417 [020] 301.935799: funcgraph_entry: 3.551us
| do_swap_page();
runtest.py-1417 [020] 301.935806: funcgraph_entry: 2.142us
| do_swap_page();
runtest.py-1417 [020] 301.935853: funcgraph_entry: 6.938us
| do_swap_page();
runtest.py-1417 [020] 301.935864: funcgraph_entry: 3.765us
| do_swap_page();
runtest.py-1417 [020] 301.935871: funcgraph_entry: 3.600us
| do_swap_page();
runtest.py-1417 [020] 301.935878: funcgraph_entry: 7.202us
| do_swap_page();
Thanks,
Yang
