[LTP] [PATCH v3 1/2] splice02: Generate input in C

Petr Vorel
2021-04-16T13:10:07Z

Hi Cyril,

...
> > Maybe one more change: INT_MAX is a bit too much, it timeouts.
> > I'll use 262144 as max allowed -n (the default on intel - 2x max pipe size).

> I guess that the main problem here is that we write one character at a
> time, which means that we spend most of the time in syscall handler code
> rather than copying the data. It may work much better if we change the
> code to write 512 bytes at a time. I.e. something as:

Sounds very reasonable, thx! I'll send v4.

Kind regards,
Petr

> #define BUFSIZE 512

> char buf[BUFSIZE];

> memset(buf, 'a', BUFSIZE);

> while (to_write > 0) {
> size_t size = to_write > BUFSIZE ? BUFSIZE : to_write;

> ...

> to_write -= written;
> }