Re: Early SPECWeb99 results on 2.5.33 with TSO on e1000

Jeff Garzik
2002-09-16T23:57:00Z

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David S. Miller wrote:
> From: Jeff Garzik <jgarzik@mandrakesoft.com>
> Date: Mon, 16 Sep 2002 19:48:37 -0400
>
> I dunno when it happened, but 2.5.x now returns EINVAL for all
> file->file cases.
>
> In 2.4.x, if sendpage is NULL, file_send_actor in mm/filemap.c faked a
> call to fops->write().
> In 2.5.x, if sendpage is NULL, EINVAL is unconditionally returned.
>
>
> What if source and destination file and offsets match?

The same data is written out. No deadlock.
(unless the attached test is wrong)

Jeff

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#include <sys/sendfile.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdio.h>

int main (int argc, char *argv[])
{
int in, out;
struct stat st;
off_t off = 0;
ssize_t rc;

in = open("test.data", O_RDONLY);
if (in < 0) {
perror("test.data read");
return 1;
}

fstat(in, &st);

out = open("test.data", O_WRONLY);
if (out < 0) {
perror("test.data write");
return 1;
}

rc = sendfile(out, in, &off, st.st_size);
if (rc < 0) {
perror("sendfile");
close(in);
unlink("out");
close(out);
return 1;
}

close(in);
close(out);
return 0;
}