From: Paolo Bonzini <pbonzini@redhat.com>
To: Orr Dvory <gidesa@gmail.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] fixing qemu busy wait
Date: Fri, 31 May 2013 16:17:20 +0200 [thread overview]
Message-ID: <51A8B0F0.9020604@redhat.com> (raw)
In-Reply-To: <CAHXCByR2OQTZ2JYrOV2ds1-vZLjmJ8Wk1knLfNSaxA27XrMPaw@mail.gmail.com>
Il 18/04/2013 20:47, Orr Dvory ha scritto:
> is this better?
Yes -- but I don't remember if this was fixed elsewhere. Can you
reproduce the problem in 1.5.0? If so, please send the patch according
to the guidelines at http://wiki.qemu.org/Contribute/SubmitAPatch.
Paolo
> diff -uprN qemu-1.4.1/gdbstub.c qemu-1.4.1-fix/gdbstub.c
> --- qemu-1.4.1/gdbstub.c 2013-04-15 23:25:18.000000000 +0300
> +++ qemu-1.4.1-fix/gdbstub.c 2013-04-18 21:35:00.000000000 +0300
> @@ -379,17 +379,22 @@ static void put_buffer(GDBState *s, cons
> {
> #ifdef CONFIG_USER_ONLY
> int ret;
> -
> + int fd_flags = fcntl (s->fd, F_GETFL, 0);
> + fcntl (s->fd, F_SETFL, fd_flags & ~O_NONBLOCK);
> while (len > 0) {
> ret = send(s->fd, buf, len, 0);
> if (ret < 0) {
>
> if (errno != EINTR && errno != EAGAIN)
> + {
> + fcntl (s->fd, F_SETFL, fd_flags);
> return;
> + }
> } else {
> buf += ret;
> len -= ret;
> }
> }
> + fcntl (s->fd, F_SETFL, fd_flags);
> #else
> qemu_chr_fe_write(s->chr, buf, len);
> #endif
> @@ -2775,6 +2780,7 @@ gdb_handlesig (CPUArchState *env, int si
> GDBState *s;
> char buf[256];
> int n;
> + int fd_flags;
>
> s = gdbserver_state;
> if (gdbserver_fd < 0 || s->fd < 0)
> @@ -2793,7 +2799,8 @@ gdb_handlesig (CPUArchState *env, int si
> connection. */
> if (s->fd < 0)
> return sig;
> -
> + fd_flags = fcntl (s->fd, F_GETFL, 0);
> + fcntl (s->fd, F_SETFL, fd_flags & ~O_NONBLOCK);
> sig = 0;
> s->state = RS_IDLE;
> s->running_state = 0;
> @@ -2810,9 +2817,11 @@ gdb_handlesig (CPUArchState *env, int si
> {
> /* XXX: Connection closed. Should probably wait for another
> connection before continuing. */
> + fcntl (s->fd, F_SETFL, fd_flags);
> return sig;
> }
> }
> + fcntl (s->fd, F_SETFL, fd_flags);
> sig = s->signal;
> s->signal = 0;
> return sig;
>
>
> On Thu, Apr 18, 2013 at 9:46 PM, Orr Dvory <gidesa@gmail.com
> <mailto:gidesa@gmail.com>> wrote:
>
> is this better?
>
> diff -uprN qemu-1.4.1/gdbstub.c qemu-1.4.1-fix/gdbstub.c
> --- qemu-1.4.1/gdbstub.c 2013-04-15 23:25:18.000000000 +0300
> +++ qemu-1.4.1-fix/gdbstub.c 2013-04-18 21:35:00.000000000 +0300
> @@ -379,17 +379,22 @@ static void put_buffer(GDBState *s, cons
> {
> #ifdef CONFIG_USER_ONLY
> int ret;
> -
> + int fd_flags = fcntl (s->fd, F_GETFL, 0);
> + fcntl (s->fd, F_SETFL, fd_flags & ~O_NONBLOCK);
> while (len > 0) {
> ret = send(s->fd, buf, len, 0);
> if (ret < 0) {
>
> if (errno != EINTR && errno != EAGAIN)
> + {
> + fcntl (s->fd, F_SETFL, fd_flags);
> return;
> + }
> } else {
> buf += ret;
> len -= ret;
> }
> }
> + fcntl (s->fd, F_SETFL, fd_flags);
> #else
> qemu_chr_fe_write(s->chr, buf, len);
> #endif
> @@ -2775,6 +2780,7 @@ gdb_handlesig (CPUArchState *env, int si
> GDBState *s;
> char buf[256];
> int n;
> + int fd_flags;
>
> s = gdbserver_state;
> if (gdbserver_fd < 0 || s->fd < 0)
> @@ -2793,7 +2799,8 @@ gdb_handlesig (CPUArchState *env, int si
> connection. */
> if (s->fd < 0)
> return sig;
> -
> + fd_flags = fcntl (s->fd, F_GETFL, 0);
> + fcntl (s->fd, F_SETFL, fd_flags & ~O_NONBLOCK);
> sig = 0;
> s->state = RS_IDLE;
> s->running_state = 0;
> @@ -2810,9 +2817,11 @@ gdb_handlesig (CPUArchState *env, int si
> {
> /* XXX: Connection closed. Should probably wait for another
> connection before continuing. */
> + fcntl (s->fd, F_SETFL, fd_flags);
> return sig;
> }
> }
> + fcntl (s->fd, F_SETFL, fd_flags);
> sig = s->signal;
> s->signal = 0;
> return sig;
>
>
> On Wed, Feb 20, 2013 at 10:38 PM, Paolo Bonzini <pbonzini@redhat.com
> <mailto:pbonzini@redhat.com>> wrote:
>
> Il 20/02/2013 20:39, Orr Dvory ha scritto:
> > if (errno != EINTR && errno != EAGAIN)
> > + /* there's no need to restore the
> > + O_NONBLOCK option. */
> > return;
> > +
>
> But it's cleaner to do it anyway. :)
>
> Paolo
>
>
>
prev parent reply other threads:[~2013-05-31 14:17 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAHXCByREfdGsVntX4ojv9BAEVD5TA0-8eiya5ky2onVBcuEv+Q@mail.gmail.com>
[not found] ` <512002D7.4090906@twiddle.net>
[not found] ` <CAHXCByQQ2Yd7yCiXzfH=5iw4UAAYCxyorawmy8ZnDCHe-6zjYA@mail.gmail.com>
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[not found] ` <5125343F.9090302@redhat.com>
[not found] ` <CAHXCByTwZN6oLPFQM50u5srL-f94TsnwMuCtvZO75L+=V9=Vow@mail.gmail.com>
2013-04-18 18:47 ` [Qemu-devel] fixing qemu busy wait Orr Dvory
2013-05-31 14:17 ` Paolo Bonzini [this message]
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