31–40 of 151 posts
Earlier quoted context omitted.
Modern AWS instance types are EBS-only.
With the exception of the High IO types (I2/I3). They still get it and the newer instances get NVMe SSDs. In other words they are making it a feature of certain types that would benefit from it.
I recently reenabled swap on my Windows machine due to frequent OOM, even with 16GB of RAM while playing Overwatch and browsing on Firefox. It seems like both of these programs allocate vast swaths of memory but then do not actually use that memory very heavily. After I turned swap back on, I did not notice any degradation in performance but my system stability skyrocketed.
Somehow that doesn't resonate with my experience. I tend to remember the cases where I can't even SSH into the box, because the fork in sshd takes minutes, as does spawning the login shell.
I'd really like some way to have swap, but still loosen the OOM killer on the biggest memory hog when the system slows down to a crawl. I haven't found that magic configuration yet.
Swap was a great idea, but its time is gone. Swap doesn't make sense anymore, hard drives have not scaled and kept up with the improvements in RAM. In the Pentium 1 era EDO RAM maxed out at 256MB/s and hard disk xfer was 10MB/s. Common RAM size was 16MB. In today's era DDR4 maxes out at 32GB/s and hard disk xfer is 500 MB/s. Common RAM size is 16GB. RAM xfer rate has grown is 320x. RAM capacity has grown 100x. Disk x…
The purpose of swap is not running things out of it. The purpose is shoveling unused data out of memory. And for that it doesn't need to be particularly fast. Swap has a lot less purpose in a world without memory leaks and extraneous functions. But in practice it's quite good at getting several gigabytes of unnecessary data out of the way, so ram can be used properly. Swap, well-used, should only take up a few percen…
Until this is fixed, I'll just keep running my systems with very small amounts of swap (say, 512MB in a system with 16GB of RAM). I'd rather the OOM killer kick in than have to REISUB or hold down the power button.
Some benchmarks with regards to the performance claims would be nice.
-PCs have a lot of RAM now
-When you allocate that much memory it's usually a bug in your own code like a size_t that overflowed. I never saw programs I would actually want to use try to allocate that much
-When using swap instead of ram, everything becomes so slow that you're screwed anyway. The UI doesn't even respond fast enough to kill whatever tries to use all that memory.
-How common is a situation where you need more memory than your ram size yet less than ram+swap size in a useful way? Usually if something needs a lot, it's really lot (and as mentioned above not desirable)
-Added complexity of making extra partition
-Added complexity if you want to use full disk encryption
-I do the opposite of using disk as ram: I put /tmp in a ramdisk of a few gigs
-Disks are slow and fast ssd's are expensive so you would't want to sacrifice their space (maybe if this changes some day...)
Swap was a great idea, but its time is gone. Swap doesn't make sense anymore, hard drives have not scaled and kept up with the improvements in RAM. In the Pentium 1 era EDO RAM maxed out at 256MB/s and hard disk xfer was 10MB/s. Common RAM size was 16MB. In today's era DDR4 maxes out at 32GB/s and hard disk xfer is 500 MB/s. Common RAM size is 16GB. RAM xfer rate has grown is 320x. RAM capacity has grown 100x. Disk x…
One of those times was on a 512MB RAM VPS, where I needed to compile something - you don't want a 512MB VPS to do a lot of compilation, but in that one instance, I was very glad I could easily just make a swap file and get on with it. The other time was on my laptop with 8 GB of RAM.
Also, even ignoring the times where swap makes possible a task which would otherwise have been impossible, you flat out ignored the content of the article. Did you even read it? If you have a long running task which allocates a lot of memory, then proceeds to only very rarely use that memory (or maybe it only needs that memory when it shuts down, or just forgot to free that memory), swap allows the system to swap out that memory and instead do something useful with it, like caching files or not killing processes. It doesn't matter that the disk is slower than RAM, if the swapped-out memory is rarely or never accessed.
I have an older Chromebook (c720), which is really quite memory starved (2GB RAM), and have experienced ChromeOS completely frying the SSD simply through prolonged tab-heavy swapping. Now, I've replaced the SSD and installed a non-Google Linux distro, and would like to limit the amount of swapping Firefox can do. I had been planning to simply use cgroups' memory features to limit the amount of memory consumed by Fire…
Firefox has a couple options which may help you get by. I can't guarantee these will fix everything but they are worth experimenting with. about:memory has various options, including a 'minimize memory usage' button and profiling tools. about:preferences has Privacy & Security > Cached Web Content > Override automatic cache management (select and set at 500MB, 1GB, or whatever works best).