17 Jul
2018
17 Jul
'18
9:41 a.m.
On Tue, 17 Jul 2018 08:43:27 +0200, Clemens Ladisch wrote:
Ricardo Biehl Pasquali wrote:
The current calculation for boundary is:
boundary = buffer_size; while (boundary * 2 <= LONG_MAX - buffer_size) boundary *= 2;
Why isn't a simpler calculation used instead? e.g.:
/* closest multiple of buffer size less or equal LONG_MAX */ boundary = LONG_MAX - LONG_MAX % buffer_size;
To ensure that the factor is a power of two.
Originally, that was not really necessary, but the algorithm is now part of the kernel/userspace interface.
Right.
I don't think we have strictly ABI issue even if relaxing this, but I also don't think it would give so much benefit, either.
thanks,
Takashi