On Sun, Nov 24, 2013 at 8:08 PM, Mark Hahn <[email protected]> wrote: >> Running a 32 bits binary on a 64 bits operating system is certainly >> possible but system call performance generally takes a hit. > > I thought it was the opposite. All 64-bit does is give you more address > space. 64-bit is slower because the code is larger and fewer instructions > fit in cache.
It's more nuanced than that. Instructions that deal with immediate values are larger but position independent code tends to be smaller and more efficient due to RIP-relative addressing. There are more registers so data gets spilled to the stack less often. Ditto for function calls, there's more opportunity to pass arguments in registers. The reason why system call performance suffers with 32 bits binaries on 64 bit hosts, is that every system call goes through a thunk that switches modes and converts arguments and the return value. -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
