From: Chen Lin <chen45464546@163.com>
To: kuba@kernel.org
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, alexander.duyck@gmail.com,
netdev@vger.kernel.org, Chen Lin <chen45464546@163.com>
Subject: Re:Re: [PATCH v2] mm: page_frag: Warn_on when frag_alloc size is bigger than PAGE_SIZE
Date: Tue, 31 May 2022 22:41:12 +0800 [thread overview]
Message-ID: <1654008072-3136-1-git-send-email-chen45464546@163.com> (raw)
In-Reply-To: <20220530122918.549ef054@kernel.org>
At 2022-05-31 02:29:18, "Jakub Kicinski" <kuba@kernel.org> wrote:
>On Mon, 30 May 2022 12:27:05 -0700 Jakub Kicinski wrote:
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index e008a3df0485..360a545ee5e8 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -5537,6 +5537,7 @@ EXPORT_SYMBOL(free_pages);
>> * sk_buff->head, or to be used in the "frags" portion of skb_shared_info.
>> */
>> static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
>> + unsigned int fragsz,
>> gfp_t gfp_mask)
>> {
>> struct page *page = NULL;
>> @@ -5549,7 +5550,7 @@ static struct page *__page_frag_cache_refill(struct page_frag_cache *nc,
>> PAGE_FRAG_CACHE_MAX_ORDER);
>> nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE;
>> #endif
>> - if (unlikely(!page))
>> + if (unlikely(!page && fragsz <= PAGE_SIZE))
>> page = alloc_pages_node(NUMA_NO_NODE, gfp, 0);
>>
>> nc->va = page ? page_address(page) : NULL;
>> @@ -5576,7 +5577,7 @@ void *page_frag_alloc_align(struct page_frag_cache *nc,
>>
>> if (unlikely(!nc->va)) {
>> refill:
>> - page = __page_frag_cache_refill(nc, gfp_mask);
>> + page = __page_frag_cache_refill(nc, fragsz, gfp_mask);
>> if (!page)
>> return NULL;
>
>Oh, well, the reuse also needs an update. We can slap a similar
>condition next to the pfmemalloc check.
The sample code above cannot completely solve the current problem.
For example, when fragsz is greater than PAGE_FRAG_CACHE_MAX_SIZE(32768),
__page_frag_cache_refill will return a memory of only 32768 bytes, so
should we continue to expand the PAGE_FRAG_CACHE_MAX_SIZE? Maybe more
work needs to be done
next prev parent reply other threads:[~2022-05-31 14:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1653752373-3172-1-git-send-email-chen45464546@163.com>
2022-05-29 23:30 ` [PATCH] mm: page_frag: Warn_on when frag_alloc size is bigger than PAGE_SIZE Andrew Morton
2022-05-30 13:39 ` [PATCH v2] " Chen Lin
2022-05-30 19:27 ` Jakub Kicinski
2022-05-30 19:29 ` Jakub Kicinski
2022-05-31 14:41 ` Chen Lin [this message]
2022-05-31 15:14 ` Jakub Kicinski
2022-05-31 15:36 ` Chen Lin
2022-05-31 15:47 ` Jakub Kicinski
2022-05-31 18:28 ` Alexander Duyck
2022-06-01 12:32 ` 愚树
2022-06-01 15:04 ` Alexander Duyck
2022-07-06 15:21 ` Maurizio Lombardi
2022-07-08 8:06 ` Maurizio Lombardi
2022-05-30 20:07 ` Andrew Morton
2022-05-31 14:43 ` [PATCH v3] " Chen Lin
2022-05-31 23:45 ` Eric Dumazet
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