[ENBD] Doubled requests

[Arne Wiebalck]

On Thu, 15 Jan 2004, Peter T. Breuer wrote:

> Can you add to the file.c code the following (which I have, and which
> I published yesterday on the group) in the fileit() routine, just above
> the write() to disk:
>
>         default:
>          case WRITE: // 1
>            DEBUG("+[%u@%Lu]", len, self->lastpoint);
>
> +          if (1) {
> +               // instrumentation
> +               static u64 lastpoint = -1LL, point;
> +               static int lastlen = -1;
> +               point = seek(fd, 0LL, SEEK_CUR);
> +               if (!(lastpoint+lastlen <= point || lastpoint >= point+len) ){
> +                       PERR("two consecutive writes to the same place!\n");
> +                       PERR("%#Lx-%#Lx and %#Lx-%Lx!\n",
> +                               lastpoint, lastpoint+lastlen,
> +                               point, point+len);
> +               }
> +               lastpoint = point;
> +               lastlen = len;
> +          }
> +
>            res = write(fd, buf, len);
>
>
> and tell me if this makes any noise under your tests.

I added it. It does not trigger. My device however still does. I am sure
I inserted it a the right place and I would have seen it (I checked it
by placing the PERR message before the "if" as a test).

Did you already add your changes to 2.4.32, i.e. shall I download and try
a newer version?

Since it seems to be sensitive to m_r (at least in my setup): what value
do you use for m_r ? maybe it's already sensitive to that and not only to
whether it's switched on or not. I am running with m_r=128 at least.

arne


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 Arne Wiebalck                        Kirchhoff Institute for Physics
                                           Technical Computer Science
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