Re:Swap, swap, swap, and bad places to work
by azernik on Friday August 09, 2019 @07:23AM
(#20653262)
You would think so, but as Rachel points out the Linux kernel displays some pathological behavior with noswap that even a tiny amount of swap lets it get around. Something weird is going on in the memory management code.
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Re:Swap, swap, swap, and bad places to work
by VectorLock on Friday August 09, 2019 @10:10AM
(#20654449)
I'm not sure what shes observing other than "feels weird" but my observation is the exact opposite, but my observations usually have some measurements to them.
Re:Swap, swap, swap, and bad places to work
by aardvarklegend on Friday August 09, 2019 @10:45AM
(#20654818)
It requires a perfect storm of just shy of 100% used memory and a lot of mmaped io. In that case the mmaped can get shunted to a handful of pages (or even one page) and so you lose all ability to have any block io larger then one page size. And every page of memory involves a fully blocking io request. Itβs most certainly real for certain workloads (databases are common).