On Sun, Dec 20, 2020 at 3:00 AM Baruch Siach [off-list ref] wrote:

Hi Willem,

On Thu, Dec 17 2020, Willem de Bruijn wrote:

quoted

On Thu, Dec 17, 2020 at 2:48 PM Jakub Kicinski [off-list ref] wrote:

quoted

On Tue, 15 Dec 2020 18:51:17 +0200 Baruch Siach wrote:

quoted

Before commit 889b8f964f2f ("packet: Kill CONFIG_PACKET_MMAP.") there
used to be a CONFIG_PACKET_MMAP config symbol that depended on
CONFIG_PACKET. The text still refers to PACKET_MMAP as the name of this
feature, implying that it can be disabled. Another naming variant is
"Packet MMAP".

Use "PACKET mmap()" everywhere to unify the terminology. Rephrase the
text the implied mmap() feature disable option.

Should we maybe say AF_PACKET mmap() ?

I don't think that the feature name PACKET_MMAP implies
CONFIG_PACKET_MMAP, or thus that the name is obsolete now that the
latter is.

Current text says "if PACKET_MMAP is not enabled ...". This clearly
implies a CONFIG_ symbol. Besides, the PACKET_MMAP term is mentioned
nowhere else in the source tree. At the very least we need to clarify
what it means.

At this point I don't think renaming will simplify anything. It is by
now referred to by that name outside the kernel, a google search
shows. It is also even the name of the documentation file
(packet_mmap.rst).

The file starts with

  PACKET_MMAP

  Abstract

  This file documents the mmap() facility available with the PACKET
  socket interface on 2.4/2.6/3.x kernels. This type of sockets is used for

That introduces the term well enough, I think.

Agreed that references to old kernel versions and the previous compile
time configurability of the feature are no longer relevant.

quoted

If it needs a rename, the setsockopt is PACKET_[RT]X_RING. So, if this
needs updating, perhaps PACKET_RING would be suitable. Or TPACKET,
based on the version definitions.

So how would you rephrase text like "PACKET_MMAP provides a size
configurable circular buffer ..."?

PACKET_RING provides a size configurable circular buffer would work,
but see previous comment.