Messages in this thread | | | Date | Wed, 25 Apr 2012 10:41:54 -0400 | From | Rik van Riel <> | Subject | Re: Over-eager swapping |
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On 04/23/2012 05:27 AM, Richard Davies wrote:
> The rrd graphs at http://imgur.com/a/Fklxr show a typical incident. > > We estimate memory used from /proc/meminfo as: > > = MemTotal - MemFree - Buffers + SwapTotal - SwapFree > > The first rrd shows memory used increasing as a VM starts, but not getting > near the 64GB of physical RAM. > > The second rrd shows the heavy swapping this VM start caused. > > The third rrd shows a multi-gigabyte jump in swap used = SwapTotal - SwapFree > > The fourth rrd shows the large load spike (from 1 to 15) caused by this swap > storm.
These are exactly the kind of swap storms that led me make the VM tweaks that got merged into 3.4-rc :)
See these commits:
fe2c2a106663130a5ab45cb0e3414b52df2fff0c 7be62de99adcab4449d416977b4274985c5fe023 aff622495c9a0b56148192e53bdec539f5e147f2 1480de0340a8d5f094b74d7c4b902456c9a06903 496b919b3bdd957d4b1727df79bfa3751bced1c1
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