On 05/29/2015 12:24 AM, Dr. David Alan Gilbert wrote: > * zhanghailiang (zhang.zhanghailiang@xxxxxxxxxx) wrote: >> This is the 5th version of COLO, here is only COLO frame part, include: VM checkpoint, >> failover, proxy API, block replication API, not include block replication. >> The block part has been sent by wencongyang: >> "[Qemu-devel] [PATCH COLO-Block v5 00/15] Block replication for continuous checkpoints" >> >> we have finished some new features and optimization on COLO (As a development branch in github), >> but for easy of review, it is better to keep it simple now, so we will not add too much new >> codes into this frame patch set before it been totally reviewed. >> >> You can get the latest integrated qemu colo patches from github (Include Block part): >> https://github.com/coloft/qemu/commits/colo-v1.2-basic >> https://github.com/coloft/qemu/commits/colo-v1.2-developing (more features) >> >> Please NOTE the difference between these two branch. >> colo-v1.2-basic is exactly same with this patch series, which has basic features of COLO. >> Compared with colo-v1.2-basic, colo-v1.2-developing has some optimization in the >> process of checkpoint, including: >> 1) separate ram and device save/load process to reduce size of extra memory >> used during checkpoint >> 2) live migrate part of dirty pages to slave during sleep time. >> Besides, we add some statistic info in colo-v1.2-developing, which you can get these stat >> info by using command 'info migrate'. > > > Hi, > I have that running now. > > Some notes: > 1) The colo-proxy is working OK until qemu quits, and then it gets an RCU problem; see below > 2) I've attached some minor tweaks that were needed to build with the 4.1rc kernel I'm using; > they're very minor changes and I don't think related to (1). > 3) I've also included some minor fixups I needed to get the -developing world > to build; my compiler is fussy about unused variables etc - but I think the code > in ram_save_complete in your -developing patch is wrong because there are two > 'pages' variables and the one in the inner loop is the only one changed. > 4) I've started trying simple benchmarks and tests now: > a) With a simple web server most requests have very little overhead, the comparison > matches most of the time; I do get quite large spikes (0.04s->1.05s) which I guess > corresponds to when a checkpoint happens, but I'm not sure why the spike is so big, > since the downtime isn't that big. I reproduce it, and we are investigating it now. > b) I tried something with more dynamic pages - the front page of a simple bugzilla What does 'dynamic pages' mean? > install; it failed the comparison every time; it took me a while to figure out > why, but it generates a unique token in it's javascript each time (for a password reset > link), and I guess the randomness used by that doesn't match on the two hosts. Yes. Thanks Wen Congyang > It surprised me, because I didn't expect this page to have much randomness > in. > > 4a is really nice - it shows the benefit of COLO over the simple checkpointing; > checkpoints happen very rarely. > > The colo-proxy rcu problem I hit shows as rcu-stalls in both primary and secondary > after the qemu quits; the backtrace of the qemu stack is: > > [<ffffffff810d8c0c>] wait_rcu_gp+0x5c/0x80 > [<ffffffff810ddb05>] synchronize_rcu+0x45/0xd0 > [<ffffffffa0a251e5>] colo_node_release+0x35/0x50 [nfnetlink_colo] > [<ffffffffa0a25795>] colonl_close_event+0xe5/0x160 [nfnetlink_colo] > [<ffffffff81090c96>] notifier_call_chain+0x66/0x90 > [<ffffffff8109154c>] atomic_notifier_call_chain+0x6c/0x110 > [<ffffffff815eee07>] netlink_release+0x5b7/0x7f0 > [<ffffffff815878bf>] sock_release+0x1f/0x90 > [<ffffffff81587942>] sock_close+0x12/0x20 > [<ffffffff812193c3>] __fput+0xd3/0x210 > [<ffffffff8121954e>] ____fput+0xe/0x10 > [<ffffffff8108d9f7>] task_work_run+0xb7/0xf0 > [<ffffffff81002d4d>] do_notify_resume+0x8d/0xa0 > [<ffffffff81722b66>] int_signal+0x12/0x17 > [<ffffffffffffffff>] 0xffffffffffffffff > > that's with both the 423a8e268acbe3e644a16c15bc79603cfe9eb084 from yesterday and > older e58e5152b74945871b00a88164901c0d46e6365e tags on colo-proxy. > I'm not sure of the right fix; perhaps it might be possible to replace the > synchronize_rcu in colo_node_release by a call_rcu that does the kfree later? > > Thanks, > > Dave > >> >> You can test any branch of the above, >> about how to test COLO, Please reference to the follow link. >> http://wiki.qemu.org/Features/COLO. >> >> COLO is still in early stage, >> your comments and feedback are warmly welcomed. >> >> Cc: netfilter-devel@xxxxxxxxxxxxxxx >> >> TODO: >> 1. Strengthen failover >> 2. COLO function switch on/off >> 2. Optimize proxy part, include proxy script. >> 1) Remove the limitation of forward network link. >> 2) Reuse the nfqueue_entry and NF_STOLEN to enqueue skb >> 3. The capability of continuous FT >> >> v5: >> - Replace the previous communication way between proxy and qemu with nfnetlink >> - Remove the 'forward device'parameter of xt_PMYCOLO, and now we use iptables command >> to set the 'forward device' >> - Turn DPRINTF into trace_ calls as Dave's suggestion >> >> v4: >> - New block replication scheme (use image-fleecing for sencondary side) >> - Adress some comments from Eric Blake and Dave >> - Add commmand colo-set-checkpoint-period to set the time of periodic checkpoint >> - Add a delay (100ms) between continuous checkpoint requests to ensure VM >> run 100ms at least since last pause. >> v3: >> - use proxy instead of colo agent to compare network packets >> - add block replication >> - Optimize failover disposal >> - handle shutdown >> >> v2: >> - use QEMUSizedBuffer/QEMUFile as COLO buffer >> - colo support is enabled by default >> - add nic replication support >> - addressed comments from Eric Blake and Dr. David Alan Gilbert >> >> v1: >> - implement the frame of colo >> >> Wen Congyang (1): >> COLO: Add block replication into colo process >> >> zhanghailiang (28): >> configure: Add parameter for configure to enable/disable COLO support >> migration: Introduce capability 'colo' to migration >> COLO: migrate colo related info to slave >> migration: Integrate COLO checkpoint process into migration >> migration: Integrate COLO checkpoint process into loadvm >> COLO: Implement colo checkpoint protocol >> COLO: Add a new RunState RUN_STATE_COLO >> QEMUSizedBuffer: Introduce two help functions for qsb >> COLO: Save VM state to slave when do checkpoint >> COLO RAM: Load PVM's dirty page into SVM's RAM cache temporarily >> COLO VMstate: Load VM state into qsb before restore it >> arch_init: Start to trace dirty pages of SVM >> COLO RAM: Flush cached RAM into SVM's memory >> COLO failover: Introduce a new command to trigger a failover >> COLO failover: Implement COLO master/slave failover work >> COLO failover: Don't do failover during loading VM's state >> COLO: Add new command parameter 'colo_nicname' 'colo_script' for net >> COLO NIC: Init/remove colo nic devices when add/cleanup tap devices >> COLO NIC: Implement colo nic device interface configure() >> COLO NIC : Implement colo nic init/destroy function >> COLO NIC: Some init work related with proxy module >> COLO: Handle nfnetlink message from proxy module >> COLO: Do checkpoint according to the result of packets comparation >> COLO: Improve checkpoint efficiency by do additional periodic >> checkpoint >> COLO: Add colo-set-checkpoint-period command >> COLO NIC: Implement NIC checkpoint and failover >> COLO: Disable qdev hotplug when VM is in COLO mode >> COLO: Implement shutdown checkpoint >> >> arch_init.c | 243 +++++++++- >> configure | 36 +- >> hmp-commands.hx | 30 ++ >> hmp.c | 14 + >> hmp.h | 2 + >> include/exec/cpu-all.h | 1 + >> include/migration/migration-colo.h | 57 +++ >> include/migration/migration-failover.h | 22 + >> include/migration/migration.h | 3 + >> include/migration/qemu-file.h | 3 +- >> include/net/colo-nic.h | 27 ++ >> include/net/net.h | 3 + >> include/sysemu/sysemu.h | 3 + >> migration/Makefile.objs | 2 + >> migration/colo-comm.c | 68 +++ >> migration/colo-failover.c | 48 ++ >> migration/colo.c | 836 +++++++++++++++++++++++++++++++++ >> migration/migration.c | 60 ++- >> migration/qemu-file-buf.c | 58 +++ >> net/Makefile.objs | 1 + >> net/colo-nic.c | 420 +++++++++++++++++ >> net/tap.c | 45 +- >> qapi-schema.json | 42 +- >> qemu-options.hx | 10 +- >> qmp-commands.hx | 41 ++ >> savevm.c | 2 +- >> scripts/colo-proxy-script.sh | 88 ++++ >> stubs/Makefile.objs | 1 + >> stubs/migration-colo.c | 58 +++ >> trace-events | 11 + >> vl.c | 39 +- >> 31 files changed, 2235 insertions(+), 39 deletions(-) >> create mode 100644 include/migration/migration-colo.h >> create mode 100644 include/migration/migration-failover.h >> create mode 100644 include/net/colo-nic.h >> create mode 100644 migration/colo-comm.c >> create mode 100644 migration/colo-failover.c >> create mode 100644 migration/colo.c >> create mode 100644 net/colo-nic.c >> create mode 100755 scripts/colo-proxy-script.sh >> create mode 100644 stubs/migration-colo.c >> >> -- >> 1.7.12.4 >> >> > -- > Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK > -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
