From: Barry Song <21cnbao@gmail.com>
To: Lei Liu <liulei.rjpt@vivo.com>
Cc: Kairui Song <ryncsn@gmail.com>, Michal Hocko <mhocko@suse.com>,
David Rientjes <rientjes@google.com>,
Shakeel Butt <shakeel.butt@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>,
Kemeng Shi <shikemeng@huaweicloud.com>,
Nhat Pham <nphamcs@gmail.com>, Baoquan He <bhe@redhat.com>,
Chris Li <chrisl@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
David Hildenbrand <david@redhat.com>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
"Liam R. Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Brendan Jackman <jackmanb@google.com>, Zi Yan <ziy@nvidia.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Chen Yu <yu.c.chen@intel.com>, Hao Jia <jiahao1@lixiang.com>,
"Kirill A. Shutemov" <kas@kernel.org>,
Usama Arif <usamaarif642@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
Christian Brauner <brauner@kernel.org>,
Mateusz Guzik <mjguzik@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andrii Nakryiko <andrii@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Fushuai Wang <wangfushuai@baidu.com>,
"open list:MEMORY MANAGEMENT - OOM KILLER" <linux-mm@kvack.org>,
open list <linux-kernel@vger.kernel.org>,
"open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)"
<cgroups@vger.kernel.org>
Subject: Re: [PATCH v0 0/2] mm: swap: Gather swap entries and batch async release
Date: Wed, 15 Oct 2025 04:42:36 +0800 [thread overview]
Message-ID: <CAGsJ_4xdvGjZ9YZnc0mk3bDfPCwxdpF_5bhcbca09j=-KBM9Mg@mail.gmail.com> (raw)
In-Reply-To: <fe38e328-5e64-44b2-9e62-f764c4b307bd@vivo.com>
>
> Hi Barry
>
> Thank you for your question. Here is the issue we are encountering:
>
> Flame graph of time distribution for douyin process exit (~400MB swapped):
> do_notify_resume 3.89%
> get_signal 3.89%
> do_signal_exit 3.88%
> do_exit 3.88%
> mmput 3.22%
> exit_mmap 3.22%
> unmap_vmas 3.08%
> unmap_page_range 3.07%
> free_swap_and_cache_nr 1.31%****
> swap_entry_range_free 1.17%****
> zram_slot_free_notify 1.11%****
If 1.11/1.31, or 85% of free_swap_and_cache_nr, comes from zram_free,
it’s clear that the swap/mm core is not the right place for this optimization.
As it involves too much complexity—for example, synchronization between
swapoff and your new threads.
> zram_free_hw_entry_dc 0.43%
> free_zspage[zsmalloc] 0.09%
Thanks
Barry
next prev parent reply other threads:[~2025-10-14 20:42 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-09 6:53 Lei Liu
2025-09-09 6:53 ` [PATCH v0 1/2] mm: swap: Gather swap entries and batch async release core Lei Liu
2025-09-10 1:39 ` kernel test robot
2025-09-10 3:12 ` kernel test robot
2025-09-09 6:53 ` [PATCH v0 2/2] mm: swap: Forced swap entries release under memory pressure Lei Liu
2025-09-10 5:36 ` kernel test robot
2025-09-09 7:30 ` [PATCH v0 0/2] mm: swap: Gather swap entries and batch async release Kairui Song
2025-09-09 9:24 ` Barry Song
2025-09-09 16:15 ` Chris Li
2025-09-09 18:01 ` Chris Li
2025-09-10 14:07 ` Lei Liu
2025-10-14 20:42 ` Barry Song [this message]
2025-09-09 15:38 ` Chris Li
2025-09-10 14:01 ` Lei Liu
2025-09-09 19:21 ` Shakeel Butt
2025-09-09 19:48 ` Suren Baghdasaryan
2025-09-10 14:14 ` Lei Liu
2025-09-10 14:56 ` Suren Baghdasaryan
2025-09-10 16:05 ` Chris Li
2025-09-10 20:12 ` Shakeel Butt
2025-09-11 3:04 ` Lei Liu
2025-09-10 15:40 ` Chris Li
2025-09-10 20:10 ` Shakeel Butt
2025-09-10 20:41 ` Suren Baghdasaryan
2025-09-10 22:10 ` T.J. Mercier
2025-09-10 22:33 ` Shakeel Butt
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