From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=39906 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OvwSo-00064R-Iv for qemu-devel@nongnu.org; Wed, 15 Sep 2010 14:12:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OvwRz-0000k9-1L for qemu-devel@nongnu.org; Wed, 15 Sep 2010 14:12:10 -0400 Received: from fmmailgate03.web.de ([217.72.192.234]:52616) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OvwRy-0000jr-H7 for qemu-devel@nongnu.org; Wed, 15 Sep 2010 14:11:19 -0400 From: =?UTF-8?q?Andreas=20F=C3=A4rber?= Date: Wed, 15 Sep 2010 20:09:19 +0200 Message-Id: <1284574159-892-1-git-send-email-andreas.faerber@web.de> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: andreas.faerber@web.de Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v6] Introduce qemu_madvise() List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Blue Swirl , Andrea Arcangeli , Alexander Graf From: Andreas F=C3=A4rber vl.c has a Sun-specific hack to supply a prototype for madvise(), but the call site has apparently moved to arch_init.c. Haiku doesn't implement madvise() in favor of posix_madvise(). OpenBSD and Solaris 10 don't implement posix_madvise() but madvise(). Check for madvise() and posix_madvise() in configure and supply qemu_madv= ise() as wrapper. Prefer madvise() over posix_madvise() due to flag availabilit= y. Convert all callers to use qemu_madvise() and QEMU_MADV_*. Note that on Solaris the warning is fixed by moving the madvise() prototy= pe, not by qemu_madvise() itself. It will help with future porting though, an= d it simplifies most call sites. v5 -> v6: * Replace two leftover instances of POSIX_MADV_NORMAL with QEMU_MADV_INVA= LID. Spotted by Blue Swirl. v4 -> v5: * Introduce QEMU_MADV_INVALID, suggested by Alexander Graf. Note that this relies on -1 not being a valid advice value. v3 -> v4: * Eliminate #ifdefs at qemu_advise() call sites. Requested by Blue Swirl. This will currently break the check in kvm-all.c by calling madvise() w= ith a supported flag, which will not fail. Ideas/patches welcome. v2 -> v3: * Reuse the *_MADV_* defines for QEMU_MADV_*. Suggested by Alexander Graf= . * Add configure check for madvise(), too. Add defines to Makefile, not QEMU_CFLAGS. Convert all callers, untested. Suggested by Blue Swirl. * Keep Solaris' madvise() prototype around. Pointed out by Alexander Graf= . * Display configure check results. v1 -> v2: * Don't rely on posix_madvise() availability, add qemu_madvise(). Suggested by Blue Swirl. Signed-off-by: Andreas F=C3=A4rber Cc: Blue Swirl Cc: Alexander Graf Cc: Andrea Arcangeli --- arch_init.c | 2 +- configure | 33 +++++++++++++++++++++++++++++++++ exec.c | 8 ++------ hw/virtio-balloon.c | 4 ++-- kvm-all.c | 15 +++++++-------- osdep.c | 18 ++++++++++++++++++ osdep.h | 35 +++++++++++++++++++++++++++++++++++ vl.c | 3 --- 8 files changed, 98 insertions(+), 20 deletions(-) diff --git a/arch_init.c b/arch_init.c index e468c0c..a910033 100644 --- a/arch_init.c +++ b/arch_init.c @@ -396,7 +396,7 @@ int ram_load(QEMUFile *f, void *opaque, int version_i= d) #ifndef _WIN32 if (ch =3D=3D 0 && (!kvm_enabled() || kvm_has_sync_mmu())) { - madvise(host, TARGET_PAGE_SIZE, MADV_DONTNEED); + qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED)= ; } #endif } else if (flags & RAM_SAVE_FLAG_PAGE) { diff --git a/configure b/configure index 4061cb7..86558eb 100755 --- a/configure +++ b/configure @@ -2069,6 +2069,31 @@ if compile_prog "" "" ; then fi =20 ########################################## +# check if we have madvise + +madvise=3Dno +cat > $TMPC << EOF +#include +#include +int main(void) { return madvise(NULL, 0, MADV_DONTNEED); } +EOF +if compile_prog "" "" ; then + madvise=3Dyes +fi + +########################################## +# check if we have posix_madvise + +posix_madvise=3Dno +cat > $TMPC << EOF +#include +int main(void) { return posix_madvise(NULL, 0, POSIX_MADV_DONTNEED); } +EOF +if compile_prog "" "" ; then + posix_madvise=3Dyes +fi + +########################################## # check if trace backend exists =20 sh "$source_path/tracetool" "--$trace_backend" --check-backend > /dev/nu= ll 2> /dev/null @@ -2226,6 +2251,8 @@ echo "KVM support $kvm" echo "fdt support $fdt" echo "preadv support $preadv" echo "fdatasync $fdatasync" +echo "madvise $madvise" +echo "posix_madvise $posix_madvise" echo "uuid support $uuid" echo "vhost-net support $vhost_net" echo "Trace backend $trace_backend" @@ -2466,6 +2493,12 @@ fi if test "$fdatasync" =3D "yes" ; then echo "CONFIG_FDATASYNC=3Dy" >> $config_host_mak fi +if test "$madvise" =3D "yes" ; then + echo "CONFIG_MADVISE=3Dy" >> $config_host_mak +fi +if test "$posix_madvise" =3D "yes" ; then + echo "CONFIG_POSIX_MADVISE=3Dy" >> $config_host_mak +fi =20 # XXX: suppress that if [ "$bsd" =3D "yes" ] ; then diff --git a/exec.c b/exec.c index 380dab5..9b5464f 100644 --- a/exec.c +++ b/exec.c @@ -2841,9 +2841,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev= , const char *name, new_block->host =3D file_ram_alloc(new_block, size, mem_path= ); if (!new_block->host) { new_block->host =3D qemu_vmalloc(size); -#ifdef MADV_MERGEABLE - madvise(new_block->host, size, MADV_MERGEABLE); -#endif + qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE)= ; } #else fprintf(stderr, "-mem-path option unsupported\n"); @@ -2858,9 +2856,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev= , const char *name, #else new_block->host =3D qemu_vmalloc(size); #endif -#ifdef MADV_MERGEABLE - madvise(new_block->host, size, MADV_MERGEABLE); -#endif + qemu_madvise(new_block->host, size, QEMU_MADV_MERGEABLE); } } =20 diff --git a/hw/virtio-balloon.c b/hw/virtio-balloon.c index 9fe3886..1e74674 100644 --- a/hw/virtio-balloon.c +++ b/hw/virtio-balloon.c @@ -51,8 +51,8 @@ static void balloon_page(void *addr, int deflate) { #if defined(__linux__) if (!kvm_enabled() || kvm_has_sync_mmu()) - madvise(addr, TARGET_PAGE_SIZE, - deflate ? MADV_WILLNEED : MADV_DONTNEED); + qemu_madvise(addr, TARGET_PAGE_SIZE, + deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED); #endif } =20 diff --git a/kvm-all.c b/kvm-all.c index 58b0404..f7c1d12 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -1031,18 +1031,17 @@ int kvm_has_xcrs(void) void kvm_setup_guest_memory(void *start, size_t size) { if (!kvm_has_sync_mmu()) { -#ifdef MADV_DONTFORK - int ret =3D madvise(start, size, MADV_DONTFORK); + int ret =3D qemu_madvise(start, size, QEMU_MADV_DONTFORK); =20 + if (ret =3D=3D -ENOTSUP) { + fprintf(stderr, + "Need MADV_DONTFORK in absence of synchronous KVM MM= U\n"); + exit(1); + } if (ret) { - perror("madvice"); + perror("qemu_madvise"); exit(1); } -#else - fprintf(stderr, - "Need MADV_DONTFORK in absence of synchronous KVM MMU\n"= ); - exit(1); -#endif } } =20 diff --git a/osdep.c b/osdep.c index 30426ff..1724a58 100644 --- a/osdep.c +++ b/osdep.c @@ -28,6 +28,7 @@ #include #include #include +#include =20 /* Needed early for CONFIG_BSD etc. */ #include "config-host.h" @@ -35,6 +36,9 @@ #ifdef CONFIG_SOLARIS #include #include +/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=3D7156) for + discussion about Solaris header problems */ +extern int madvise(caddr_t, size_t, int); #endif =20 #ifdef CONFIG_EVENTFD @@ -139,6 +143,20 @@ void qemu_vfree(void *ptr) =20 #endif =20 +int qemu_madvise(void *addr, size_t len, int advice) +{ + if (advice =3D=3D QEMU_MADV_INVALID) { + return -ENOTSUP; + } +#if defined(CONFIG_MADVISE) + return madvise(addr, len, advice); +#elif defined(CONFIG_POSIX_MADVISE) + return posix_madvise(addr, len, advice); +#else + return -ENOTSUP; +#endif +} + int qemu_create_pidfile(const char *filename) { char buffer[128]; diff --git a/osdep.h b/osdep.h index 1cdc7e2..6716281 100644 --- a/osdep.h +++ b/osdep.h @@ -90,6 +90,41 @@ void *qemu_memalign(size_t alignment, size_t size); void *qemu_vmalloc(size_t size); void qemu_vfree(void *ptr); =20 +#define QEMU_MADV_INVALID -1 + +#if defined(CONFIG_MADVISE) + +#define QEMU_MADV_WILLNEED MADV_WILLNEED +#define QEMU_MADV_DONTNEED MADV_DONTNEED +#ifdef MADV_DONTFORK +#define QEMU_MADV_DONTFORK MADV_DONTFORK +#else +#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID +#endif +#ifdef MADV_MERGEABLE +#define QEMU_MADV_MERGEABLE MADV_MERGEABLE +#else +#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID +#endif + +#elif defined(CONFIG_POSIX_MADVISE) + +#define QEMU_MADV_WILLNEED POSIX_MADV_WILLNEED +#define QEMU_MADV_DONTNEED POSIX_MADV_DONTNEED +#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID +#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID + +#else /* no-op */ + +#define QEMU_MADV_WILLNEED QEMU_MADV_INVALID +#define QEMU_MADV_DONTNEED QEMU_MADV_INVALID +#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID +#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID + +#endif + +int qemu_madvise(void *addr, size_t len, int advice); + int qemu_create_pidfile(const char *filename); =20 #ifdef _WIN32 diff --git a/vl.c b/vl.c index 3f45aa9..d352d18 100644 --- a/vl.c +++ b/vl.c @@ -80,9 +80,6 @@ #include #include #include -/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=3D7156) for - discussion about Solaris header problems */ -extern int madvise(caddr_t, size_t, int); #endif #endif #endif --=20 1.7.2.2