5 ms·
One downside: you will probably need a bit more memory to do the same work. An unmentioned benefit: better ASLR, for what that's worth. > A 64 bit system means
by gok 7y ago
One downside: you will probably need a bit more memory to do the same work. An unmentioned benefit: better ASLR, for what that's worth.
> A 64 bit system means that RAM can be accessed in 8 byte read/writes per instruction.
I mean...kind of but that's probably not really what's happening in this benchmark. Firstly, in that test `memset()` is surely using NEON instructions internally on both ARMv7 and AArch64, which can load/store up to 32 bytes in a single instruction. Further that test is really just showing the bandwidth of the memory controller. I'm not sure why AArch64 would matter there. It's possible that `memset` / `memcmp` are using smarter prefetching instructions in AArch64.
- m4rtink 7y agoI wonder if using zram or zswap can help "eat" those overly long pointers in RAM via compression ?
- cellularmitosis 7y agoI've never understood why zswap decompresses the pages before writing them out to disk. Disk IO is the slowest part of the whole chain, you've already paid to compress the data, why on earth would you throw that away AND use up more disk IO?
- phh 7y agoCompressing improves disk's bandwidth
- m4rtink 7y agoMy guess is that this is due to some inherent limitations of the Linux kernel swap mechanism ? Possibly so that you can safely disable zswap at runtime (you can) ? Or quite possibly no one implemented it just yet & writing uncompressed pages is transparently compatible with what normal swapping does.