[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] migration: fix divide-by-zero introduced by sle
From: |
Anthony Liguori |
Subject: |
Re: [Qemu-devel] [PATCH] migration: fix divide-by-zero introduced by sleep time accounting |
Date: |
Thu, 16 May 2013 16:12:12 -0500 |
User-agent: |
Notmuch/0.15.2+77~g661dcf8 (http://notmuchmail.org) Emacs/23.3.1 (x86_64-pc-linux-gnu) |
Anthony Liguori <address@hidden> writes:
> If current_time == (initial_time + sleep_time), since
> sleep_time == BUFFER_DELAY, time_spent will be 0 resulting in a
> divide-by-zero when computing bandwidth.
>
> This was introduced by:
>
> commit 7161082c8d8cf167c508976887a0a63f4db92b51
> Author: Juan Quintela <address@hidden>
> Date: Fri Feb 1 12:41:38 2013 +0100
>
> migration: don't account sleep time for calculating bandwidth
>
> Cc: Juan Quintela <address@hidden>
> Reported-by: Mike Roth <address@hidden>
> Signed-off-by: Anthony Liguori <address@hidden>
Nack
Mike reports that this breaks migration in a different way. He's
sending a full revert of the offending commit.
Regards,
Anthony Liguori
> ---
> migration.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration.c b/migration.c
> index 3eb0fad..70ae7a9 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -539,7 +539,7 @@ static void *migration_thread(void *opaque)
> break;
> }
> current_time = qemu_get_clock_ms(rt_clock);
> - if (current_time >= initial_time + BUFFER_DELAY) {
> + if ((current_time - sleep_time) >= initial_time + BUFFER_DELAY) {
> uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes;
> uint64_t time_spent = current_time - initial_time - sleep_time;
> double bandwidth = transferred_bytes / time_spent;
> --
> 1.8.0