Thread (78 messages) flat view 78 messages, 7 authors, 2014-08-19

RE: [PATCH RFC v4 net-next 00/26] BPF syscall, maps, verifier, samples, llvm

From: David Laight <hidden>
Date: 2014-08-13 08:54:29
Also in: lkml, netdev

From: Of Alexei Starovoitov
one more RFC...

Major difference vs previous set is a new 'load 64-bit immediate' eBPF insn.
Which is first 16-byte instruction. It shows how eBPF ISA can be extended
while maintaining backward compatibility, but mainly it cleans up eBPF
program access to maps and improves run-time performance.
Wouldn't it be more sensible to follow the scheme used by a lot of cpus
and add a 'load high' instruction (follow with 'add' or 'or').
It still takes 16 bytes to load a 64bit immediate value, but the instruction
size remains constant.
There is nothing to stop any JIT software detecting the instruction pair.

	David
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help