From: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
To: Yosry Ahmed <yosryahmed@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Nhat Pham <nphamcs@gmail.com>,
Chengming Zhou <chengming.zhou@linux.dev>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [RFC PATCH 5/9] mm: zswap: remove zswap_same_filled_pages_enabled
Date: Fri, 29 Mar 2024 15:02:10 +0100 [thread overview]
Message-ID: <19d5cdee-2868-41bd-83d5-6da75d72e940@maciej.szmigiero.name> (raw)
In-Reply-To: <CAJD7tkYo90ynKfBcWyMZLu7r-GJj3egnnJyGiJ5T2SN-Tn3d9A@mail.gmail.com>
On 29.03.2024 03:14, Yosry Ahmed wrote:
> On Thu, Mar 28, 2024 at 1:06 PM Yosry Ahmed <yosryahmed@google.com> wrote:
>>
>> On Thu, Mar 28, 2024 at 12:11 PM Johannes Weiner <hannes@cmpxchg.org> wrote:
>>>
>>> On Mon, Mar 25, 2024 at 11:50:13PM +0000, Yosry Ahmed wrote:
>>>> There is no logical reason to refuse storing same-filled pages more
>>>> efficiently and opt for compression. Remove the userspace knob.
>>>>
>>>> Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
>>>
>>> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
>>>
>>> I also think the non_same_filled_pages_enabled option should go
>>> away. Both of these tunables are pretty bizarre.
>>
>> Happy to remove both in the next version :)
>
> I thought non_same_filled_pages_enabled was introduced with the
> initial support for same-filled pages, but it was introduced
> separately (and much more recently):
> https://lore.kernel.org/all/7dbafa963e8bab43608189abbe2067f4b9287831.1641247624.git.maciej.szmigiero@oracle.com/
>
> I am CCing Maciej to hear more about the use case for this.
Thanks for CCing me.
I introduced "non_same_filled_pages_enabled" a few years ago to
enable using zswap in a lightweight mode where it is only used for
its ability to store same-filled pages effectively.
As far as I remember, there were some interactions between full
zswap and the cgroup memory controller - like, it made it easier
for an aggressive workload to exceed its cgroup memory.high limits.
On the other hand, "same_filled_pages_enabled" sounds like some kind
of a debugging option since I don't see any real reason to disable it
either.
Thanks,
Maciej
next prev parent reply other threads:[~2024-03-29 14:02 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-25 23:50 [RFC PATCH 0/9] zswap: store zero-filled pages more efficiently Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 1/9] mm: zswap: always shrink in zswap_store() if zswap_pool_reached_full Yosry Ahmed
2024-03-26 21:49 ` Nhat Pham
2024-03-27 2:21 ` Chengming Zhou
2024-03-28 19:09 ` Johannes Weiner
2024-03-25 23:50 ` [RFC PATCH 2/9] mm: zswap: refactor storing to the tree out of zswap_store() Yosry Ahmed
2024-03-27 2:25 ` Chengming Zhou
2024-03-27 22:29 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 3/9] mm: zswap: refactor limit checking from zswap_store() Yosry Ahmed
2024-03-27 2:42 ` Chengming Zhou
2024-03-27 22:30 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 4/9] mm: zswap: move more same-filled pages checks outside of zswap_store() Yosry Ahmed
2024-03-26 21:57 ` Nhat Pham
2024-03-27 2:39 ` Chengming Zhou
2024-03-27 22:32 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 5/9] mm: zswap: remove zswap_same_filled_pages_enabled Yosry Ahmed
2024-03-26 22:01 ` Nhat Pham
2024-03-27 2:44 ` Chengming Zhou
2024-03-27 22:34 ` Yosry Ahmed
2024-03-28 19:11 ` Johannes Weiner
2024-03-28 20:06 ` Yosry Ahmed
2024-03-29 2:14 ` Yosry Ahmed
2024-03-29 14:02 ` Maciej S. Szmigiero [this message]
2024-03-29 17:44 ` Johannes Weiner
2024-03-29 18:22 ` Yosry Ahmed
2024-04-01 10:37 ` Maciej S. Szmigiero
2024-04-01 18:29 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 6/9] mm: zswap: drop support for non-zero same-filled pages handling Yosry Ahmed
2024-03-27 11:25 ` Chengming Zhou
2024-03-27 16:40 ` Nhat Pham
2024-03-27 22:38 ` Yosry Ahmed
2024-03-28 19:31 ` Johannes Weiner
2024-03-28 20:23 ` Yosry Ahmed
2024-03-28 21:07 ` Johannes Weiner
2024-03-28 23:19 ` Nhat Pham
2024-03-29 2:05 ` Yosry Ahmed
2024-03-29 4:27 ` Yosry Ahmed
2024-03-29 17:37 ` Johannes Weiner
2024-03-29 18:56 ` Yosry Ahmed
2024-03-29 21:17 ` Johannes Weiner
2024-03-29 22:29 ` Yosry Ahmed
2024-03-28 23:33 ` Nhat Pham
2024-03-29 2:07 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 7/9] mm: zswap: store zero-filled pages without a zswap_entry Yosry Ahmed
2024-03-28 8:12 ` Chengming Zhou
2024-03-28 18:45 ` Yosry Ahmed
2024-03-28 19:38 ` Johannes Weiner
2024-03-28 20:29 ` Yosry Ahmed
2024-03-25 23:50 ` [RFC PATCH 8/9] mm: zswap: do not check the global limit for zero-filled pages Yosry Ahmed
2024-03-28 8:15 ` Chengming Zhou
2024-03-25 23:50 ` [RFC PATCH 9/9] mm: zswap: use zswap_entry_free() for partially initialized entries Yosry Ahmed
2024-03-28 8:31 ` Chengming Zhou
2024-03-28 18:49 ` Yosry Ahmed
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