[Qemu-devel] [RESEND PATCH V5 0/6] coroutine: mmap stack memory and stack size

[Peter Lieven]

I decided to split this from the rest of the Qemu RSS usage series as
it contains the more or less non contentious patches.

I omitted the MAP_GROWSDOWN flag in mmap as we are not 100% sure which
side effects it has.

I kept the guard page which is now nicely makes the stacks visible in
smaps. The old version of the relevent patch lacked the MAP_FIXED flag
in the second call to mmap.

The last patch which reduces the stack size of coroutines to 64kB
may be omitted if its found to risky.

v4->v5:
 - Patch 1: check if _SC_THREAD_STACK_MIN is defined
 - Patch 1: guard against sysconf(_SC_THREAD_STACK_MIN) returning -1 [Eric]

v3->v4:
 - Patch 1: add a static function to adjust the stack size [Richard]
 - Patch 1: round up the stack size to multiple of the pagesize.

v2->v3:
 - Patch 1,6: adjusted commit message to mention the guard page [Markus]

v1->v2:
 - Patch 1: added an architecture dependend guard page [Richard]
 - Patch 1: avoid stacks smaller than _SC_THREAD_STACK_MIN [Richard]
 - Patch 1: use mmap+mprotect instead of mmap+mmap [Richard]
 - Patch 5: u_int32_t -> uint32_t [Richard]
 - Patch 5: only available if stack grows down

Peter Lieven (6):
  oslib-posix: add helpers for stack alloc and free
  coroutine: add a macro for the coroutine stack size
  coroutine-ucontext: use helper for allocating stack memory
  coroutine-sigaltstack: use helper for allocating stack memory
  oslib-posix: add a configure switch to debug stack usage
  coroutine: reduce stack size to 64kB

 configure                    | 19 ++++++++++
 include/qemu/coroutine_int.h |  2 ++
 include/sysemu/os-posix.h    | 23 ++++++++++++
 util/coroutine-sigaltstack.c |  7 ++--
 util/coroutine-ucontext.c    |  9 +++--
 util/coroutine-win32.c       |  2 +-
 util/oslib-posix.c           | 83 ++++++++++++++++++++++++++++++++++++++++++++
 7 files changed, 135 insertions(+), 10 deletions(-)

-- 
1.9.1