From 2c41a5f9e355412bdab3d92329ae5637bbdb08f1 Mon Sep 17 00:00:00 2001 From: aliguori Date: Thu, 11 Sep 2008 14:32:27 +0000 Subject: [PATCH] Make sure to read siginfo from signalfd Otherwise, we'll idle at 100% cpu. Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5195 c046a42c-6fe2-441c-8c8c-71466251a162 --- block-raw-posix.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/block-raw-posix.c b/block-raw-posix.c index f6dc72ae54..0587950c8f 100644 --- a/block-raw-posix.c +++ b/block-raw-posix.c @@ -449,6 +449,30 @@ static void qemu_aio_poll(void *opaque) { RawAIOCB *acb, **pacb; int ret; + size_t offset; + union { + struct qemu_signalfd_siginfo siginfo; + char buf[128]; + } sig; + + /* try to read from signalfd, don't freak out if we can't read anything */ + offset = 0; + while (offset < 128) { + ssize_t len; + + len = read(aio_sig_fd, sig.buf + offset, 128 - offset); + if (len == -1 && errno == EINTR) + continue; + if (len == -1 && errno == EAGAIN) { + /* there is no natural reason for this to happen, + * so we'll spin hard until we get everything just + * to be on the safe side. */ + if (offset > 0) + continue; + } + + offset += len; + } for(;;) { pacb = &first_aio; @@ -498,6 +522,9 @@ void qemu_aio_init(void) sigprocmask(SIG_BLOCK, &mask, NULL); aio_sig_fd = qemu_signalfd(&mask); + + fcntl(aio_sig_fd, F_SETFL, O_NONBLOCK); + #if !defined(QEMU_IMG) && !defined(QEMU_NBD) qemu_set_fd_handler2(aio_sig_fd, NULL, qemu_aio_poll, NULL, NULL); #endif -- 2.30.2