Re: [PATCH 00/11] mm: lru related cleanups

Alex Shi
2020-12-10T09:28:56Z

Hi Yu,

btw, after this patchset, to do cacheline alignment on each of lru lists
are possible, so did you try that to see performance changes?

Thanks
Alex

在 2020/12/8 上午6:09, Yu Zhao 写道:
> The cleanups are intended to reduce the verbosity in lru list
> operations and make them less error-prone. A typical example
> would be how the patches change __activate_page():
>
> static void __activate_page(struct page *page, struct lruvec *lruvec)
> {
> if (!PageActive(page) && !PageUnevictable(page)) {
> - int lru = page_lru_base_type(page);
> int nr_pages = thp_nr_pages(page);
>
> - del_page_from_lru_list(page, lruvec, lru);
> + del_page_from_lru_list(page, lruvec);
> SetPageActive(page);
> - lru += LRU_ACTIVE;
> - add_page_to_lru_list(page, lruvec, lru);
> + add_page_to_lru_list(page, lruvec);
> trace_mm_lru_activate(page);
>
> There are a few more places like __activate_page() and they are
> unnecessarily repetitive in terms of figuring out which list a page
> should be added onto or deleted from. And with the duplicated code
> removed, they are easier to read, IMO.
>
> Patch 1 to 5 basically cover the above. Patch 6 and 7 make code more
> robust by improving bug reporting. Patch 8, 9 and 10 take care of
> some dangling helpers left in header files. Patch 11 isn't strictly a
> clean-up patch, but it seems still relevant to include it here.
>
> Yu Zhao (11):
> mm: use add_page_to_lru_list()
> mm: shuffle lru list addition and deletion functions
> mm: don't pass "enum lru_list" to lru list addition functions
> mm: don't pass "enum lru_list" to trace_mm_lru_insertion()
> mm: don't pass "enum lru_list" to del_page_from_lru_list()
> mm: add __clear_page_lru_flags() to replace page_off_lru()
> mm: VM_BUG_ON lru page flags
> mm: fold page_lru_base_type() into its sole caller
> mm: fold __update_lru_size() into its sole caller
> mm: make lruvec_lru_size() static
> mm: enlarge the "int nr_pages" parameter of update_lru_size()
>
> include/linux/memcontrol.h | 10 +--
> include/linux/mm_inline.h | 115 ++++++++++++++-------------------
> include/linux/mmzone.h | 2 -
> include/linux/vmstat.h | 6 +-
> include/trace/events/pagemap.h | 11 ++--
> mm/compaction.c | 2 +-
> mm/memcontrol.c | 10 +--
> mm/mlock.c | 3 +-
> mm/swap.c | 50 ++++++--------
> mm/vmscan.c | 21 ++----
> 10 files changed, 91 insertions(+), 139 deletions(-)
>