Bug 1045089

(In reply to Laura Novich from comment #0)
> Description of problem:
> 1. nodesuspend - there is no information on how exactly to set this command.
> Default values are not listed, and it is not clear what the disk, mem, and
> especially hybrid arguments do.
> 
> 2. node-memory-tune - there is a lot that doesn't make sense here. The MAN
> page says "sets the number of pages to scan before the shared memory service
> goes to sleep" 
>       A - what is the "memory service" and is this shared for the guest and
> host or guest and guest? 
>       B - is this an actual service as in a daemon?

It's KSM.

>       C - is this command related to
> https://bugzilla.redhat.com/show_bug.cgi?id=ivshmem which has been pushed to
> 7.1? If yes, should this be pushed as well? 

No. Personally I think it's trivial to move to 7.1, but I'd like hear your opinions.

Checked the libvirt doc with man virsh command in libvirt-1.1.1-19,I can see the details note for the nodesuspend and node-memory-tune command,also they are clearly for use, so this bug can be mark verified.
#man virsh 
--
1. nodesuspend 
       nodesuspend [target] [duration]
           Puts the node (host machine) into a system-wide sleep state and
           schedule the node's Real-Time-Clock interrupt to resume the node
           after the time duration specified by duration is out.  target
           specifies the state to which the host will be suspended to, it can
           be "mem" (suspend to RAM), "disk" (suspend to disk), or "hybrid"
           (suspend to both RAM and disk).  duration specifies the time
           duration in seconds for which the host has to be suspended, it
           should be at least 60 seconds.
2. node-memory-tune
       node-memory-tune [shm-pages-to-scan] [shm-sleep-millisecs] shm-merge-
       across-nodes
           Allows you to display or set the node memory parameters.  shm-
           pages-to-scan can be used to set the number of pages to scan
           before the shared memory service goes to sleep; shm-sleep-
           millisecs can be used to set the number of millisecs the shared
           memory service should sleep before next scan; shm-merge-across-
           nodes specifies if pages from different numa nodes can be merged.
           When set to 0, only pages which physically reside in the memory
           area of same NUMA node can be merged. When set to 1, pages from
           all nodes can be merged. Default to 1.
       Note: Currently the "shared memory service" only means KSM (Kernel
           Samepage Merging).

could reprodce it on libvirt-1.0.6-1.el7.x86_64.
-------------------------------------------------
#man virsh
       nodesuspend [target] [duration]
           Puts the node (host machine) into a system-wide sleep state such as
           Suspend-to-RAM, Suspend-to-Disk or Hybrid-Suspend and sets up a
           Real-Time-Clock interrupt to fire (to wake up the node) after a
           time delay specified by the 'duration' parameter. The duration time
           should be at least 60 seconds.

       node-memory-tune [shm-pages-to-scan] [shm-sleep-millisecs]
           Allows you to display or set the node memory parameters.  shm-
           pages-to-scan can be used to set the number of pages to scan before
           the shared memory service goes to sleep; shm-sleep-millisecs can be
           used to set the number of millisecs the shared memory service
           should sleep before next scan; shm-merge-across-nodes specifies if
           pages from different numa nodes can be merged. When set to 0, only
           pages which physically reside in the memory area of same NUMA node
           can be merged. When set to 1, pages from all nodes can be merged.
           Default to 1.




Have fixed and verified it on libvirt-1.1.1-23.el7.x86_64:
       nodesuspend [target] [duration]
           Puts the node (host machine) into a system-wide sleep state and schedule the node's Real-Time-Clock interrupt to
           resume the node after the time duration specified by duration is out.  target specifies the state to which the host
           will be suspended to, it can be "mem" (suspend to RAM), "disk" (suspend to disk), or "hybrid" (suspend to both RAM
           and disk).  duration specifies the time duration in seconds for which the host has to be suspended, it should be at
           least 60 seconds.


       node-memory-tune [shm-pages-to-scan] [shm-sleep-millisecs] shm-merge-across-nodes
           Allows you to display or set the node memory parameters.  shm-pages-to-scan can be used to set the number of pages
           to scan before the shared memory service goes to sleep; shm-sleep-millisecs can be used to set the number of
           millisecs the shared memory service should sleep before next scan; shm-merge-across-nodes specifies if pages from
           different numa nodes can be merged. When set to 0, only pages which physically reside in the memory area of same
           NUMA node can be merged. When set to 1, pages from all nodes can be merged. Default to 1.

           Note: Currently the "shared memory service" only means KSM (Kernel Samepage Merging).

This request was resolved in Red Hat Enterprise Linux 7.0.

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