[v3,00/10] *** A Method for evaluating dirty page rate ***

Message

Zheng Chuan Aug. 17, 2020, 3:20 a.m. UTC

v2 -> v3:
    fix size_t compile warning
    fix codestyle checked by checkpatch.pl

v1 -> v2:
    use g_rand_new() to generate rand_buf
    move RAMBLOCK_FOREACH_MIGRATABLE into migration/ram.h
    add skip_sample_ramblock to filter sampled ramblock
    fix multi-numa vm coredump when query dirtyrate
    rename qapi interface and rename some structures and functions
    succeed to compile by appling each patch
    add test for migrating vm

Sometimes it is neccessary to evaluate dirty page rate before migration.
Users could decide whether to proceed migration based on the evaluation
in case of vm performance loss due to heavy workload.
Unlikey simulating dirtylog sync which could do harm on runnning vm,
we provide a sample-hash method to compare hash results for samping page.
In this way, it would have hardly no impact on vm performance.

Evaluate the dirtypage rate both on running and migration vm.
The VM specifications for migration are as follows:
- VM use 4-K page;
- the number of VCPU is 32;
- the total memory is 32Gigabit;
- use 'mempress' tool to pressurize VM(mempress 4096 1024);
- migration bandwidth is 1GB/s

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|                      |  running  |                  migrating                    |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| no mempress          |   4MB/s   |          8MB/s      (migrated success)        |
------------------------------------------------------------------------------------
| mempress 4096 1024   |  1188MB/s |   536MB/s ~ 1044MB/s (cpu throttle triggered) |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| mempress 4096 4096   |  4152MB/s |     608MB/s ~ 4125MB/s (migation failed)      |
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Test dirtyrate by qmp command like this:
1.  virsh qemu-monitor-command [vmname] '{"execute":"calc-dirty-rate", "arguments": {"calc-time": [sleep-time]}}'; 
2.  sleep specific time which is a bit larger than sleep-time
3.  virsh qemu-monitor-command [vmname] '{"execute":"query-dirty-rate"}'

Further test dirtyrate by libvirt api like this:
virsh getdirtyrate [vmname] [sleep-time]

Zheng Chuan (10):
  migration/dirtyrate: Add get_dirtyrate_thread() function
  migration/dirtyrate: Add RamlockDirtyInfo to store sampled page info
  migration/dirtyrate: Add dirtyrate statistics series functions
  migration/dirtyrate: move RAMBLOCK_FOREACH_MIGRATABLE into ram.h
  migration/dirtyrate: Record hash results for each sampled page
  migration/dirtyrate: Compare page hash results for recorded sampled
    page
  migration/dirtyrate: skip sampling ramblock with size below
    MIN_RAMBLOCK_SIZE
  migration/dirtyrate: Implement get_sample_page_period() and
    block_sample_page_period()
  migration/dirtyrate: Implement calculate_dirtyrate() function
  migration/dirtyrate: Implement
    qmp_cal_dirty_rate()/qmp_get_dirty_rate() function

 migration/Makefile.objs |   1 +
 migration/dirtyrate.c   | 448 ++++++++++++++++++++++++++++++++++++++++++++++++
 migration/dirtyrate.h   |  86 ++++++++++
 migration/ram.c         |  11 +-
 migration/ram.h         |  10 ++
 qapi/migration.json     |  42 +++++
 6 files changed, 588 insertions(+), 10 deletions(-)
 create mode 100644 migration/dirtyrate.c
 create mode 100644 migration/dirtyrate.h

Comments

[e-mail] Aug. 17, 2020, 3:19 a.m. UTC | #1

Patchew URL: https://patchew.org/QEMU/[e-mail]/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: [e-mail]
Subject: [PATCH v3 00/10] *** A Method for evaluating dirty page rate ***

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 * [new tag]         patchew/[e-mail] -> patchew/[e-mail]
Switched to a new branch 'test'
ce6fe0d migration/dirtyrate: Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function
96ce007 migration/dirtyrate: Implement calculate_dirtyrate() function
42642d4 migration/dirtyrate: Implement get_sample_page_period() and block_sample_page_period()
3a4d4a2 migration/dirtyrate: skip sampling ramblock with size below MIN_RAMBLOCK_SIZE
31f35b7 migration/dirtyrate: Compare page hash results for recorded sampled page
a3d582d migration/dirtyrate: Record hash results for each sampled page
85c6447 migration/dirtyrate: move RAMBLOCK_FOREACH_MIGRATABLE into ram.h
c7c94cc migration/dirtyrate: Add dirtyrate statistics series functions
a76c0d0 migration/dirtyrate: Add RamlockDirtyInfo to store sampled page info
7f6092c migration/dirtyrate: Add get_dirtyrate_thread() function

=== OUTPUT BEGIN ===
1/10 Checking commit 7f6092c52d5c (migration/dirtyrate: Add get_dirtyrate_thread() function)
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#26: 
new file mode 100644

total: 0 errors, 1 warnings, 115 lines checked

Patch 1/10 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
2/10 Checking commit a76c0d08e93d (migration/dirtyrate: Add RamlockDirtyInfo to store sampled page info)
3/10 Checking commit c7c94cc4c17d (migration/dirtyrate: Add dirtyrate statistics series functions)
4/10 Checking commit 85c64473ab70 (migration/dirtyrate: move RAMBLOCK_FOREACH_MIGRATABLE into ram.h)
ERROR: Macros with multiple statements should be enclosed in a do - while loop
#63: FILE: migration/ram.h:42:
+#define RAMBLOCK_FOREACH_NOT_IGNORED(block)            \
+    INTERNAL_RAMBLOCK_FOREACH(block)                   \
+        if (ramblock_is_ignored(block)) {} else

ERROR: trailing statements should be on next line
#65: FILE: migration/ram.h:44:
+        if (ramblock_is_ignored(block)) {} else

ERROR: Macros with multiple statements should be enclosed in a do - while loop
#67: FILE: migration/ram.h:46:
+#define RAMBLOCK_FOREACH_MIGRATABLE(block)             \
+    INTERNAL_RAMBLOCK_FOREACH(block)                   \
+        if (!qemu_ram_is_migratable(block)) {} else

ERROR: trailing statements should be on next line
#69: FILE: migration/ram.h:48:
+        if (!qemu_ram_is_migratable(block)) {} else

ERROR: braces {} are necessary for all arms of this statement
#69: FILE: migration/ram.h:48:
+        if (!qemu_ram_is_migratable(block)) {} else
[...]
+        if (!qemu_ram_is_migratable(block)) {} else
[...]

total: 5 errors, 0 warnings, 45 lines checked

Patch 4/10 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

5/10 Checking commit a3d582d88093 (migration/dirtyrate: Record hash results for each sampled page)
6/10 Checking commit 31f35b73e761 (migration/dirtyrate: Compare page hash results for recorded sampled page)
7/10 Checking commit 3a4d4a207812 (migration/dirtyrate: skip sampling ramblock with size below MIN_RAMBLOCK_SIZE)
8/10 Checking commit 42642d45cf29 (migration/dirtyrate: Implement get_sample_page_period() and block_sample_page_period())
9/10 Checking commit 96ce00742d23 (migration/dirtyrate: Implement calculate_dirtyrate() function)
10/10 Checking commit ce6fe0d124c5 (migration/dirtyrate: Implement qmp_cal_dirty_rate()/qmp_get_dirty_rate() function)
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/[e-mail]/testing.checkpatch/?type=message.
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