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] mm: store zero pages to be swapped out in a bitmap 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=87ed8zmvla.fsf@linux.intel.com \
--to=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=chengming.zhou@linux.dev \
--cc=david@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=hughd@google.com \
--cc=kernel-team@meta.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=nphamcs@gmail.com \
--cc=shakeel.butt@linux.dev \
--cc=usamaarif642@gmail.com \
--cc=willy@infradead.org \
--cc=ying.huang@intel.com \
--cc=yosryahmed@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.