[Qemu-devel] [PATCH 0/2] linux-user: Change mmap_lock to rwlock

[Richard Henderson]

The objective here is to avoid serializing the first-fault
and no-fault aarch64 sve loads.

When I first thought of this, we still had tb_lock protecting
code generation and merely needed mmap_lock to prevent mapping
changes while doing so.  Now (or very soon), tb_lock is gone
and user-only code generation dual-purposes the mmap_lock for
the code generation lock.

There are two other legacy users of mmap_lock within linux-user,
for ppc and mips.  I believe these are dead code from before these
ports were converted to use tcg atomics.

Thoughts?


r~


Based-on: <address@hidden> [tcg-next]
Based-on: <address@hidden> [v5 SVE]


Richard Henderson (2):
  exec: Split mmap_lock to mmap_rdlock/mmap_wrlock
  linux-user: Use pthread_rwlock_t for mmap_rd/wrlock

 include/exec/exec-all.h    |  6 ++--
 accel/tcg/cpu-exec.c       |  8 ++---
 accel/tcg/translate-all.c  |  4 +--
 bsd-user/mmap.c            | 18 +++++++++---
 exec.c                     |  6 ++--
 linux-user/elfload.c       |  2 +-
 linux-user/mips/cpu_loop.c |  2 +-
 linux-user/mmap.c          | 60 +++++++++++++++++++++++++-------------
 linux-user/ppc/cpu_loop.c  |  2 +-
 linux-user/syscall.c       |  4 +--
 target/arm/sve_helper.c    | 10 ++-----
 target/xtensa/op_helper.c  |  2 +-
 12 files changed, 76 insertions(+), 48 deletions(-)

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2.17.1