This is a request for comments as well as a request for help :-)
I've been experimenting with making TCGContext per-thread, so that we can
run most of tcg_gen_code in parallel. I've made some progress,
but haven't yet got it to work.
My guess is that the TCG stack is still global instead of per-vCPU
(it's been global since tmp_buf was removed from CPUState, right?),
but I'm having trouble following that code so most likely I'm wrong.
Any help would be appreciated--please disregard minor nits, I want
to see whether I can make this work to then take measurements
to decide whether this is worth the trouble.
- Patch 1 is a trivial doc fixup, feel free to pick it up
- Patches 2-3 remove *tbs[] to use a binary search tree instead.
This removes the assumption in tb_find_pc that *tbs[] are ordered
by tc_ptr, thereby allowing us to generate code regardless of
its location on the host (as we do after patch 6).
- Patch 4 addresses a reporting issue: ever since we embedded the
struct TB's in code_gen_buffer (6e3b2bfd6), we have been
misreporting the size of the generated code. Not a huge deal,
but I noticed while I was working on this.
- Patches 5-7 make TCGContext per-thread in softmmu. I have put there
some XXX's to note that I'm aware of those issues, so don't worry
too much about those--except of course if you have any input on
what the cause of the race(s) might be.
Thanks,
Emilio
