public inbox for [email protected]
 help / color / mirror / Atom feed
From: Chenliang Li <[email protected]>
To: [email protected], [email protected]
Cc: [email protected], [email protected],
	[email protected], [email protected],
	[email protected], Chenliang Li <[email protected]>
Subject: [PATCH v3 0/5] io_uring/rsrc: coalescing multi-hugepage registered buffers
Date: Mon, 13 May 2024 16:22:55 +0800	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: CGME20240513082306epcas5p2fd8ea6fd88b2c4ab1d17b1508fe2af97@epcas5p2.samsung.com

Registered buffers are stored and processed in the form of bvec array,
each bvec element typically points to a PAGE_SIZE page but can also work
with hugepages. Specifically, a buffer consisting of a hugepage is
coalesced to use only one hugepage bvec entry during registration.
This coalescing feature helps to save both the space and DMA-mapping time.

However, currently the coalescing feature doesn't work for multi-hugepage
buffers. For a buffer with several 2M hugepages, we still split it into
thousands of 4K page bvec entries while in fact, we can just use a
handful of hugepage bvecs.

This patch series enables coalescing registered buffers with more than
one hugepages. It optimizes the DMA-mapping time and saves memory for
these kind of buffers.

Perf diff of 8M(4*2M) hugepage fixed buffer fio test:

fio/t/io_uring -d64 -s32 -c32 -b8388608 -p0 -B1 -F0 -n1 -O1 -r10 \
-R1 /dev/nvme0n1

Before          After           Symbol

5.90%                           [k] __blk_rq_map_sg
3.70%                           [k] dma_direct_map_sg
3.07%                           [k] dma_pool_alloc
1.12%                           [k] sg_next
                +0.44%          [k] dma_map_page_attrs

First three patches prepare for adding the multi-hugepage coalescing
into buffer registration, the 4th patch enables the feature. The 5th
patch add test cases for this feature in liburing.

-----------------
Changes since v2:

- Modify the loop iterator increment to make code cleaner
- Minor fix to the return procedure in coalesced buffer account
- Correct commit messages
- Add test cases in liburing

v2 : https://lore.kernel.org/io-uring/[email protected]/T/#t

Changes since v1:

- Split into 4 patches
- Fix code style issues
- Rearrange the change of code for cleaner look
- Add speciallized pinned page accounting procedure for coalesced
  buffers
- Reordered the newly add fields in imu struct for better compaction

v1 : https://lore.kernel.org/io-uring/[email protected]/T/#u

Chenliang Li (5):
  io_uring/rsrc: add hugepage buffer coalesce helpers
  io_uring/rsrc: store folio shift and mask into imu
  io_uring/rsrc: add init and account functions for coalesced imus
  io_uring/rsrc: enable multi-hugepage buffer coalescing
  liburing: add test cases for hugepage registered buffers

 io_uring/rsrc.c | 217 +++++++++++++++++++++++++++++++++++++++---------
 io_uring/rsrc.h |  12 +++
 2 files changed, 191 insertions(+), 38 deletions(-)


base-commit: 59b28a6e37e650c0d601ed87875b6217140cda5d
-- 
2.34.1


       reply	other threads:[~2024-05-13  8:29 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20240513082306epcas5p2fd8ea6fd88b2c4ab1d17b1508fe2af97@epcas5p2.samsung.com>
2024-05-13  8:22 ` Chenliang Li [this message]
     [not found]   ` <CGME20240513082308epcas5p3c38ce4d44fa1613988bbae84eaec41b9@epcas5p3.samsung.com>
2024-05-13  8:22     ` [PATCH v3 1/5] io_uring/rsrc: add hugepage buffer coalesce helpers Chenliang Li
     [not found]   ` <CGME20240513082310epcas5p27576a80eae3ee09e40102b179ce46fa9@epcas5p2.samsung.com>
2024-05-13  8:22     ` [PATCH v3 2/5] io_uring/rsrc: store folio shift and mask into imu Chenliang Li
     [not found]   ` <CGME20240513082311epcas5p3556d301a1f1faca0c6b613555324861e@epcas5p3.samsung.com>
2024-05-13  8:22     ` [PATCH v3 3/5] io_uring/rsrc: add init and account functions for coalesced imus Chenliang Li
     [not found]   ` <CGME20240513082313epcas5p2a781d3393e4bf92d13d04ac62bb28fb7@epcas5p2.samsung.com>
2024-05-13  8:22     ` [PATCH v3 4/5] io_uring/rsrc: enable multi-hugepage buffer coalescing Chenliang Li
2024-05-13 12:11       ` Anuj gupta
     [not found]   ` <CGME20240513082314epcas5p309fa70575596792b5c9923ce76a3778f@epcas5p3.samsung.com>
2024-05-13  8:23     ` [PATCH v3 5/5] liburing: add test cases for hugepage registered buffers Chenliang Li
2024-05-13 12:09   ` [PATCH v3 0/5] io_uring/rsrc: coalescing multi-hugepage " Anuj gupta
2024-05-13 13:40     ` Jens Axboe
     [not found]       ` <CGME20240514001813epcas5p455c8a3dd6f2164626a526c05f7fd92c4@epcas5p4.samsung.com>
2024-05-14  0:18         ` Chenliang Li
     [not found]     ` <CGME20240514001443epcas5p362c60c233ed2aecdb5e144099b44d9be@epcas5p3.samsung.com>
2024-05-14  0:14       ` [PATCH v3 4/5] io_uring/rsrc: enable multi-hugepage buffer coalescing Chenliang Li
     [not found]     ` <CGME20240514001620epcas5p10d8c08ffc3dbd746213df21e47df19f7@epcas5p1.samsung.com>
2024-05-14  0:16       ` [PATCH v3 0/5] io_uring/rsrc: coalescing multi-hugepage registered buffers Chenliang Li

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 \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    [email protected] \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox