[Qemu-devel] [PATCH] Prefer posix_madvise() over madvise()

[Andreas Färber]

From: Andreas Färber <address@hidden>

vl.c has a Sun-specific hack to supply a prototype for madvise(),
but the call site has apparently moved to arch_init.c.
The underlying issue is that madvise() is not a POSIX function,
therefore Solaris' _POSIX_C_SOURCE suppresses the prototype.

Haiku doesn't implement madvise() at all.

Where functionality equivalent to that of madvise() is provided,
use the POSIX function posix_madvise().
http://www.opengroup.org/onlinepubs/9699919799/functions/posix_madvise.html

Remaining madvise() users:
exec.c: limited to __linux__ and/or MADV_MERGEABLE (no POSIX equivalent)
kvm-all.c: limited to MADV_DONTFORK (no POSIX equivalent),
           otherwise runtime error if !kvm_has_sync_mmu()
hw/virtio-balloon.c: limited to __linux__

Signed-off-by: Andreas Färber <address@hidden>
Cc: Blue Swirl <address@hidden>
---
 arch_init.c |    2 +-
 vl.c        |    3 ---
 2 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index e468c0c..fa39557 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -396,7 +396,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_id)
 #ifndef _WIN32
             if (ch == 0 &&
                 (!kvm_enabled() || kvm_has_sync_mmu())) {
-                madvise(host, TARGET_PAGE_SIZE, MADV_DONTNEED);
+                posix_madvise(host, TARGET_PAGE_SIZE, POSIX_MADV_DONTNEED);
             }
 #endif
         } else if (flags & RAM_SAVE_FLAG_PAGE) {
diff --git a/vl.c b/vl.c
index 3f45aa9..d352d18 100644
--- a/vl.c
+++ b/vl.c
@@ -80,9 +80,6 @@
 #include <net/if.h>
 #include <syslog.h>
 #include <stropts.h>
-/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
-   discussion about Solaris header problems */
-extern int madvise(caddr_t, size_t, int);
 #endif
 #endif
 #endif
-- 
1.7.2.2