Re: [PATCH v4 9/9] mm/lru: revise the comments of lru_lock

[Johannes Weiner <hannes@cmpxchg.org>]

On Tue, Nov 19, 2019 at 08:23:23PM +0800, Alex Shi wrote:
> Since we changed the pgdat->lru_lock to lruvec->lru_lock, it's time to
> fix the incorrect comments in code. Also fixed some zone->lru_lock comment
> error from ancient time. etc.
> 
> Originally-from: Hugh Dickins <hughd@google.com>

You can resubmit a patch written by somebody else, but you need to
preserve authorship such that git can attribute it properly:

	From: Hugh Dickins <hughd@google.com>

in the patch header, as well as

	Signed-off-by: Hugh Dickins <hughd@google.com>

in the changelog tags. It should look something like this:

---
From: Hugh Dickins <hughd@google.com>
Subject: [PATCH] mm/memcg: update lru_lock Doc and comments

Update scattered references from "zone_lru_lock" to "lruvec->lru_lock"
(in low-level descriptions) or "lruvec lock" (where that reads better).

In the course of doing so, update lock ordering comments in mm/rmap.c
and mm/filemap.c and Documentation/cgroups/memory.txt - slightly, with
no attempt to be complete (swap_lock, in particular, left out-of-date).
Remove allusions to set_page_dirty under page_remove_rmap: gone in v3.9.

memcg_test.txt looks quite out-of-date: just give LRU a short paragraph.
Replaced zone by node throughout unevictable-lru.txt (except for stats).
Leave Documentation/locking/lockstat.txt untouched this time: it doesn't
matter if that still refers to zone->lru_lock, along with other history.

I struggled to understand the comment above move_pages_to_lru() (surely
it never calls page_referenced()), and eventually realized that most of
it had got separated from shrink_active_list(): move that comment back.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
---