On Tue, Nov 22, 2005 at 11:52:04AM -0500, Benjamin LaHaise wrote:Hello Andi et al,
The patch below converts x86-64 to use r10 as the current pointer instead of gs:pcurrent. This results in a ~34KB savings in the code segment of the kernel. I've tested this with running a few regular applications, plus a few 32 bit binaries. If this patch is interesting, it probably makes sense to merge the thread info structure into the task_struct so that the assembly bits for syscall entry can be cleaned up. Comments?
I think you could get most of the benefit by just dropping
the volatile and "memory" from read_pda(). With that gcc would
usually CSE current into a register and it would would work essentially
the same way with only minor more .text overhead, but r10 would be still