d947f36560
Currently, tc_calc_xmittime and tc_calc_xmitsize round from double to int three times — once when they call tc_core_time2tick / tc_core_tick2time (whose argument is int), once when those functions return (their return value is int), and then finally when the tc_calc_* functions return. This leads to extremely granular and inaccurate conversions. As a result, for example, on my test system (where tick_in_usec=15.625, clock_factor=1, and hz=1000000000) for a bitrate of 1Gbps, all tc htb burst values between 0 and 999 bytes get encoded as 0 ticks; all values between 1000 and 1999 bytes get encoded as 15 ticks (equivalent to 960 bytes); all values between 2000 and 2999 bytes as 31 ticks (1984 bytes); etc. The patch changes the code so these calculations are done internally in floating-point, and only rounded to integer values when the value is returned. It also changes tc_calc_xmittime to round its calculated value up, rather than down, to ensure that the calculated time is actually sufficient for the requested size. Signed-off-by: Jonathan Lennox <jonathan.lennox@8x8.com> Signed-off-by: David Ahern <dsahern@kernel.org>
This is a set of utilities for Linux networking.
Information:
https://wiki.linuxfoundation.org/networking/iproute2
Download:
http://www.kernel.org/pub/linux/utils/net/iproute2/
Stable version repository:
git://git.kernel.org/pub/scm/network/iproute2/iproute2.git
Development repository:
git://git.kernel.org/pub/scm/network/iproute2/iproute2-next.git
Compatibility
-------------
A new release of iproute2 is done with each kernel version, but
there is a wide range of compatibility. Newer versions of iproute2
will still work with older kernels, but there are some limitations.
If an iproute2 command with a new feature is used with an older
kernel, the kernel may report an error or silently ignore the new
attribute. Likewise if older iproute2 is used with an newer kernel,
it is not possible to use or see new features. The range of
compatibility extends back as far as the oldest supported Long Term
Support (LTS) kernel version.
How to compile this.
--------------------
1. libdbm
arpd needs to have the berkeleydb development libraries. For Debian
users this is the package with a name like libdbX.X-dev.
DBM_INCLUDE points to the directory with db_185.h which
is the include file used by arpd to get to the old format Berkeley
database routines. Often this is in the db-devel package.
2. make
The makefile will automatically build a config.mk file which
contains definitions of libraries that may or may not be available
on the system such as: ATM, ELF, MNL, and SELINUX.
3. include/uapi
This package includes matching sanitized kernel headers because
the build environment may not have up to date versions. See Makefile
if you have special requirements and need to point at different
kernel include files.
Stephen Hemminger
stephen@networkplumber.org
David Ahern
dsahern@gmail.com