From: Andi Kleen <ak@linux.intel.com>
To: Usama Arif <usamaarif642@gmail.com>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org,
shakeel.butt@linux.dev, david@redhat.com, ying.huang@intel.com,
hughd@google.com, willy@infradead.org, yosryahmed@google.com,
nphamcs@gmail.com, chengming.zhou@linux.dev,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com
Subject: Re: [PATCH v5 1/2] mm: store zero pages to be swapped out in a bitmap
Date: Fri, 14 Jun 2024 07:45:37 -0700 [thread overview]
Message-ID: <87ed8zmvla.fsf@linux.intel.com> (raw)
In-Reply-To: <20240614100902.3469724-2-usamaarif642@gmail.com> (Usama Arif's message of "Fri, 14 Jun 2024 11:07:05 +0100")
Usama Arif <usamaarif642@gmail.com> writes:
> Approximately 10-20% of pages to be swapped out are zero pages [1].
> Rather than reading/writing these pages to flash resulting
> in increased I/O and flash wear, a bitmap can be used to mark these
> pages as zero at write time, and the pages can be filled at
> read time if the bit corresponding to the page is set.
> With this patch, NVMe writes in Meta server fleet decreased
> by almost 10% with conventional swap setup (zswap disabled).
>
> [1] https://lore.kernel.org/all/20171018104832epcms5p1b2232e2236258de3d03d1344dde9fce0@epcms5p1/
But how much did the CPU time increase? Surely the new loop is not free?
-Andi
next prev parent reply other threads:[~2024-06-14 14:51 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-14 10:07 [PATCH v5 0/2] " Usama Arif
2024-06-14 10:07 ` [PATCH v5 1/2] " Usama Arif
2024-06-14 12:05 ` Chengming Zhou
2024-06-14 18:41 ` Yosry Ahmed
2024-06-14 14:45 ` Andi Kleen [this message]
2024-06-14 15:02 ` Usama Arif
2024-06-14 18:36 ` Yosry Ahmed
2024-06-14 20:23 ` Nhat Pham
2024-06-14 10:07 ` [PATCH v5 2/2] mm: remove code to handle same filled pages Usama Arif
2024-06-14 12:07 ` Chengming Zhou
2024-06-14 18:41 ` Yosry Ahmed
2024-06-14 20:25 ` Nhat Pham
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