I just wanted to let people know that as a result of a discussion on 
linux-mm I've added support for the new slab allocator to my collectl 
utility, now making it real easy to dynamically monitor allocations 
along with all the other types of monitoring collectl does.  I've also 
put together a webpage at http://collectl.sourceforge.net/SlabInfo.html 
to give a taste of how this all works as well as to show a few different 
types of output.
-mark

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In keeping with the spirit of adding new useful features when they help 
solve real world problems, I've added this ability to collectl as a 
direct result of a problem we were recently having when doing some 
network performance testing.  It turned out all the interrupts were 
being processed by cpu0 (this was on an 8-core system) but all collectl 
told us was the aggregate number!  Once we moved to a NIC/driver that 
supported multiple queues that could distribute interrupts to multiple 
CPUs it only made sense to enhance collectl to let us verify that this 
was indeed happening - I personally find examining /proc/interrupts for 
changes more trouble than it's worth.

In any event, the following is an example of how collectl can present 
this data, first summarized by CPU:

#Time     Cpu0 Cpu1 Cpu2 Cpu3 Cpu4 Cpu5 Cpu6 Cpu7
12:49:55  4828  16K 1000  16K   18  16K  16K    0
12:49:56  4804  16K 1000  16K    0  16K  16K    0
12:49:57  4811  16K 1000  16K   18  16K  16K    0
12:49:58  4789  16K 1000  16K    0  17K  16K   44

and here by the type of the interrupt itself:

# INTERRUPT DETAILS
#          Int    Cpu0   Cpu1   Cpu2   Cpu3   Cpu4   Cpu5   Cpu6   Cpu7 
  Type            Device(s)
12:48:50   082       0      0      0   7731      0      0      0      
0   PCI-MSI-X       eth2 (queue 0)
12:48:50   098       0      0      0      0   2037      0      0      
0   PCI-MSI-X       eth2 (queue 2)
12:48:50   122       0      0   2240      0      0      0      0      
0   PCI-MSI-X       eth2 (queue 5)
12:48:50   138       0   7084      0      0      0      0      0      
0   PCI-MSI-X       eth2 (queue 7)
12:48:50   154       0      0      0      0      0   7723      0      
0   PCI-MSI-X       eth3 (queue 0)
12:48:50   162    9082      0      0      0      0      0      0      
0   PCI-MSI-X       eth3 (queue 1)
12:48:50   178       0      0      0      0      0      0   8253      
0   PCI-MSI-X       eth3 (queue 3)
12:48:50   210       0      0      0      0      0      0 ...
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Just a quick note on this.  If you've been staying away from collectl because it didn't support V4 of nfs, I finally got around to adding it.  One thing that's kind of cool is if you run the command "collectl -sF --home", you'll see a top-like command that displays most of the nfs stats on all types of the systems' nfs client/servers for versions 2,3 and 4.  You can read a little more about it at: http://collectl.sourceforge.net/NfsInfo.html

While I was at it I also added buddyinfo monitoring, so you can literally watch your fragment distribution change in real-time using the command "collectl -sB --home" as described here - http://collectl.sourceforge.net/BuddyInfo.html.  I'm still not sure how one can make the most out of this information or if I'm displaying it in the most useful manner, but as always all feedback is welcome, preferably on the collectl mailing list collectl-interest@lists.sourceforge.net.

-mark


 

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