Messages in this thread | | | Subject | Re: [PATCH net-next] page_pool: Rename frag_users to frag_cnt | From | Yunsheng Lin <> | Date | Fri, 15 Dec 2023 20:34:05 +0800 |
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On 2023/12/15 19:58, Ilias Apalodimas wrote: > Hi Yunsheng, > > On Fri, 15 Dec 2023 at 13:10, Yunsheng Lin <linyunsheng@huawei.com> wrote: >> >> On 2023/12/15 15:31, Ilias Apalodimas wrote: >>> Since [0] got merged, it's clear that 'pp_ref_count' is used to track >>> the number of users for each page. On struct_page though we have >>> a member called 'frag_users'. Despite of what the name suggests this is >>> not the number of users. It instead represents the number of fragments of >>> the current page. When we have a single page this is set to one. When we >>> split the page this is set to the actual number of frags and later used >>> in page_pool_drain_frag() to infer the real number of users. >>> >>> So let's rename it to something that matches the description above >>> >>> [0] >>> Link: https://lore.kernel.org/netdev/20231212044614.42733-2-liangchen.linux@gmail.com/ >>> Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> >>> --- >>> include/net/page_pool.h | 2 +- >>> net/core/page_pool.c | 8 ++++---- >>> 2 files changed, 5 insertions(+), 5 deletions(-) >>> >>> diff --git a/include/net/page_pool.h b/include/net/page_pool.h >>> index 813c93499f20..957cd84bb3f4 100644 >>> --- a/include/net/page_pool.h >>> +++ b/include/net/page_pool.h >>> @@ -158,7 +158,7 @@ struct page_pool { >>> u32 pages_state_hold_cnt; >>> unsigned int frag_offset; >>> struct page *frag_page; >>> - long frag_users; >>> + long frag_cnt; >> >> I would rename it to something like refcnt_bais to mirror the pagecnt_bias >> in struct page_frag_cache. > > Sure > >> >>> >>> #ifdef CONFIG_PAGE_POOL_STATS >>> /* these stats are incremented while in softirq context */ >>> diff --git a/net/core/page_pool.c b/net/core/page_pool.c >>> index 9b203d8660e4..19a56a52ac8f 100644 >>> --- a/net/core/page_pool.c >>> +++ b/net/core/page_pool.c >>> @@ -659,7 +659,7 @@ EXPORT_SYMBOL(page_pool_put_page_bulk); >>> static struct page *page_pool_drain_frag(struct page_pool *pool, >>> struct page *page) >>> { >>> - long drain_count = BIAS_MAX - pool->frag_users; >>> + long drain_count = BIAS_MAX - pool->frag_cnt; >> >> drain_count = pool->refcnt_bais; > > I think this is a typo right? This still remains
It would be better to invert logic too, as it is mirroring:
https://elixir.bootlin.com/linux/v6.7-rc5/source/mm/page_alloc.c#L4745
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