Supports for new slab allocator now in latest release

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

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"[email protected]"> [email protected] </a>

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      0   6417   PCI-MSI-X       eth3 (queue 7)
12:48:50   218       1      0      0      0      0      0      0      0   PCI-MSI         eth0

You can also look at all CPU loads and interrupts together like this:

# SINGLE CPU STATISTICS
# CPU USER NICE SYS WAIT IRQ SOFT STEAL IDLE INTRPT

07:09:28       0     0    0    0    0    0    0     0  100     16
07:09:28       1     0    0    0    0    0    0     0  100      0
07:09:28       2     0    0    0    0    0    0     0  100    999
07:09:28       3     0    0    0    0    0    0     0  100     16

For those not familiar with collectl, you can collect virtually everything all the existing linux 'stat' utilitie provide plus a lot more such as processes (including I/O stats), Infininband, Quadrics, Slab, Lustre and more. Plus a lot more feature too numerous to list but there's a pretty good summary here - http://collectl.sourceforge.net/Features.html

But don't take my word for it, check out the website at http://collectl.sourceforge.net/ where you can see a pretty good set of examples in the documentation and even follow the tutorial.

-mark

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 [email protected].

-mark