Messages in this thread | | | From | Linus Torvalds <> | Date | Sun, 27 Oct 2019 10:03:35 -0400 | Subject | Re: [RFC PATCH 04/10] pipe: Use head and tail pointers for the ring, not cursor and length [ver #2] |
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This still has signs of that earlier series:
On Wed, Oct 23, 2019 at 4:17 PM David Howells <dhowells@redhat.com> wrote: > > if (rem >= ibuf->len) { > *obuf = *ibuf; > ibuf->ops = NULL; > - pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); > - pipe->nrbufs--; > + tail++; > + pipe_commit_read(pipe, tail); > } else { > if (!pipe_buf_get(pipe, ibuf)) > goto out_free;
with those odd "pipe_commit_read/write()" helpers.
They make no sense, and they don't make things more legible.
It's shorter and more obvious to just write
pipe->head = head;
than it is to write
pipe_commit_write(pipe, head);
Even when the addition of the notifications, it's all under the pipe->wait.lock, so it's all just regular assignments.
Now, if at some point it starts doing fancy lockless things, at _that_ point the updates might become more complex, but that's a potential future thing that wouldn't be relevant for a while, and isn't a reason to make the code more obscure now.
Hmm?
Linus
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