[PATCH tip v8 0/5] Simple wait queue support

From: Daniel Wagner
Date: Fri Feb 19 2016 - 03:51:49 EST


From: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>

Hi,

This version of the series got some compile time. I tried
to weed out the incompatible-pointer-types warning in mainline.
In the last verison I included two patches to fix those warnings.
In the meantime these patches are either already in mainline
or on the way. I found a couple more of them and sent out fixes.
Overall it looks quite good on that front. So I don't think
-Werror=incompatible-pointer-types will be a big desaster. Famous last
words...

I was able to build alpha, arm32, arm64, cris10, frv, ia64, mips32,
mips64, m68k, ppc64, s390, sparc32, sparc64, um_x86_64 and x86_64 with
toolchains I got. There are a comple of missing architectures though
like avr32, blackfin, cris32, m32r, parsic, parsic64, ppc32, sh32,
sh64, tile and xtensa for which I have toolchains but they are broken
in some way beyound easy fixing.

These patches are against

tip/sched/core 3223d052b79eb9b620d170584c417d60a8bfd649

also available as git tree:

git://git.kernel.org/pub/scm/linux/kernel/git/wagi/linux.git tip-swait

cheers,
daniel

changes since v7:
- dropped random fixes for incompatible-pointer-types warning
- sent out patches for fixing incompatible-pointer-types warnings

changes since v6:
- fixed a couple of incompatible-pointer-types errors
- fixed a missing KVM ARM wait -> swait update

changes since v5:
- unconditionally add -Werror=incompatible-pointer-types
- updated KVM statistics in commit message
- rebased on tip/sched/core
- added ack-by PeterZ

changes since v4:
- replaced patch #2 which tried to force to compiler to
exit with an error by using compile time assertion type
check macros. Instead use -Werror=incompatible-pointer-types
to tell the compiler to barf loudly.
- fixed wrong API usage in patch 4 as reported by Boqun.

changes since v3
- rebased it on tip/sched/core (KVM bits have changed slightly)
- added compile time type check assertion
- added non lazy version of swake_up_locked()

changes since v2
- rebased again on tip/master. The patches apply
cleanly on v4.3-rc6 too.
- fixed up mips
- reordered patches to avoid lockdep warning when doing bissect.
- remove unnecessary initialization of rsp->rda in rcu_init_one().

changes since v1 (PATCH v0)
- rebased and fixed some typos found by cross building
for S390, ARM and powerpc. For some unknown reason didn't catch
them last time.
- dropped completion patches because it is not clear yet
how to handle complete_all() calls hard-irq/atomic contexts
and swake_up_all.

changes since v0 (RFC v0)
- promoted the series to PATCH state instead of RFC
- fixed a few fallouts with build all and some cross compilers
such ARM, PowerPC, S390.
- Added the simple waitqueue transformation for KVM from -rt
including some numbers requested by Paolo.
- Added a commit message to PeterZ's patch. Hope he likes it.

[I got the numbering wrong in v1, so instead 'PATCH v1' you find it
as 'PATCH v0' series]

v7: https://lkml.org/lkml/2016/1/29/305
v6: https://lkml.org/lkml/2016/1/28/462
v5: https://lkml.org/lkml/2015/11/30/318
v4: https://lwn.net/Articles/665655/
v3: https://lwn.net/Articles/661415/
v2: https://lwn.net/Articles/660628/
v1: https://lwn.net/Articles/656942/
v0: https://lwn.net/Articles/653586/

Daniel Wagner (2):
kbuild: Add option to turn incompatible pointer check into error
rcu: Do not call rcu_nocb_gp_cleanup() while holding rnp->lock

Marcelo Tosatti (1):
KVM: use simple waitqueue for vcpu->wq

Paul Gortmaker (1):
rcu: use simple wait queues where possible in rcutree

Peter Zijlstra (Intel) (1):
wait.[ch]: Introduce the simple waitqueue (swait) implementation

Makefile | 3 +
arch/arm/kvm/arm.c | 8 +-
arch/arm/kvm/psci.c | 4 +-
arch/mips/kvm/mips.c | 8 +-
arch/powerpc/include/asm/kvm_host.h | 4 +-
arch/powerpc/kvm/book3s_hv.c | 23 +++--
arch/s390/include/asm/kvm_host.h | 2 +-
arch/s390/kvm/interrupt.c | 4 +-
arch/x86/kvm/lapic.c | 6 +-
include/linux/kvm_host.h | 5 +-
include/linux/swait.h | 172 ++++++++++++++++++++++++++++++++++++
kernel/rcu/tree.c | 24 ++---
kernel/rcu/tree.h | 12 +--
kernel/rcu/tree_plugin.h | 32 ++++---
kernel/sched/Makefile | 2 +-
kernel/sched/swait.c | 123 ++++++++++++++++++++++++++
virt/kvm/async_pf.c | 4 +-
virt/kvm/kvm_main.c | 17 ++--
18 files changed, 382 insertions(+), 71 deletions(-)
create mode 100644 include/linux/swait.h
create mode 100644 kernel/sched/swait.c

--
2.5.0