[Qemu-devel] [PATCH for-2.12] iothread: fix breakage on windows

[Qemu-devel] [PATCH for-2.12] iothread: fix breakage on windows

[Peter Xu]

OOB can enable iothread for parsing even on Windows.  We need some tunes
to enable that on Windows otherwise it'll break Windows users.  This
patch fixes the breakage on Windows with qemu-system-ppc.exe.

Reported-by: Howard Spoelstra <hsp.cat7@gmail.com>
Tested-by: Howard Spoelstra <hsp.cat7@gmail.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 iothread.c       | 4 ++++
 util/aio-win32.c | 4 +++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/iothread.c b/iothread.c
index 1b3463cb00..9f52270ae1 100644
--- a/iothread.c
+++ b/iothread.c
@@ -31,11 +31,15 @@ typedef ObjectClass IOThreadClass;
 #define IOTHREAD_CLASS(klass) \
    OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
 
+#ifdef CONFIG_LINUX
 /* Benchmark results from 2016 on NVMe SSD drives show max polling times around
  * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32
  * workloads.
  */
 #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL
+#else
+#define IOTHREAD_POLL_MAX_NS_DEFAULT 0ULL
+#endif
 
 static __thread IOThread *my_iothread;
 
diff --git a/util/aio-win32.c b/util/aio-win32.c
index d6d5e02f00..a67b00c6ad 100644
--- a/util/aio-win32.c
+++ b/util/aio-win32.c
@@ -410,5 +410,7 @@ void aio_context_setup(AioContext *ctx)
 void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
                                  int64_t grow, int64_t shrink, Error **errp)
 {
-    error_setg(errp, "AioContext polling is not implemented on Windows");
+    if (max_ns) {
+        error_setg(errp, "AioContext polling is not implemented on Windows");
+    }
 }
-- 
2.14.3

Re: [Qemu-devel] [PATCH for-2.12] iothread: fix breakage on windows

[Paolo Bonzini]

On 22/03/2018 09:56, Peter Xu wrote:
> OOB can enable iothread for parsing even on Windows.  We need some tunes
> to enable that on Windows otherwise it'll break Windows users.  This
> patch fixes the breakage on Windows with qemu-system-ppc.exe.
> 
> Reported-by: Howard Spoelstra <hsp.cat7@gmail.com>
> Tested-by: Howard Spoelstra <hsp.cat7@gmail.com>
> Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  iothread.c       | 4 ++++
>  util/aio-win32.c | 4 +++-
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/iothread.c b/iothread.c
> index 1b3463cb00..9f52270ae1 100644
> --- a/iothread.c
> +++ b/iothread.c
> @@ -31,11 +31,15 @@ typedef ObjectClass IOThreadClass;
>  #define IOTHREAD_CLASS(klass) \
>     OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
>  
> +#ifdef CONFIG_LINUX
>  /* Benchmark results from 2016 on NVMe SSD drives show max polling times around
>   * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32
>   * workloads.
>   */
>  #define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL
> +#else
> +#define IOTHREAD_POLL_MAX_NS_DEFAULT 0ULL
> +#endif
>  
>  static __thread IOThread *my_iothread;
>  
> diff --git a/util/aio-win32.c b/util/aio-win32.c
> index d6d5e02f00..a67b00c6ad 100644
> --- a/util/aio-win32.c
> +++ b/util/aio-win32.c
> @@ -410,5 +410,7 @@ void aio_context_setup(AioContext *ctx)
>  void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
>                                   int64_t grow, int64_t shrink, Error **errp)
>  {
> -    error_setg(errp, "AioContext polling is not implemented on Windows");
> +    if (max_ns) {
> +        error_setg(errp, "AioContext polling is not implemented on Windows");
> +    }
>  }
> 

Queued, thanks.

Paolo