On Wed, Aug 04, 2021 at 08:04:35PM -0400, Alex Xu (Hello71) wrote:
> Before this patch, the following program prints 4096 and hangs.
> Afterwards, it prints 8192 and exits successfully. Note that you may
> need to increase your RLIMIT_NOFILE before running the program.
>
> int main() {
> int pipefd[2];
> for (int i = 0; i < 1025; i++)
> if (pipe(pipefd) == -1)
> return 1;
> size_t bufsz = fcntl(pipefd[1], F_GETPIPE_SZ);
> printf("%zd\n", bufsz);
> char *buf = calloc(bufsz, 1);
> write(pipefd[1], buf, bufsz);
> read(pipefd[0], buf, bufsz-1);
> write(pipefd[1], buf, 1);
> }
>
> Signed-off-by: Alex Xu (Hello71) <alex_y_xu@xxxxxxxx>
> ---
Is this due to the changes that happened in 5.5? If so, a cc: stable
and a fixes tag would be nice to have :)
> See discussion at https://lore.kernel.org/lkml/1628086770.5rn8p04n6j.none@localhost/.
This can go up in the changelog text too.
thanks,
greg k-h
