From: Dennis Zhou <dennis@kernel.org>
To: Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
Christoph Lameter <cl@linux.com>
Cc: Vlad Buslov <vladbu@mellanox.com>,
kernel-team@fb.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 04/12] percpu: manage chunks based on contig_bits instead of free_bytes
Date: Wed, 27 Feb 2019 21:18:31 -0500 [thread overview]
Message-ID: <20190228021839.55779-5-dennis@kernel.org> (raw)
In-Reply-To: <20190228021839.55779-1-dennis@kernel.org>
When a chunk becomes fragmented, it can end up having a large number of
small allocation areas free. The free_bytes sorting of chunks leads to
unnecessary checking of chunks that cannot satisfy the allocation.
Switch to contig_bits sorting to prevent scanning chunks that may not be
able to service the allocation request.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
---
mm/percpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/percpu.c b/mm/percpu.c
index b40112b2fc59..c996bcffbb2a 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -234,7 +234,7 @@ static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
if (chunk->free_bytes < PCPU_MIN_ALLOC_SIZE || chunk->contig_bits == 0)
return 0;
- return pcpu_size_to_slot(chunk->free_bytes);
+ return pcpu_size_to_slot(chunk->contig_bits * PCPU_MIN_ALLOC_SIZE);
}
/* set the pointer to a chunk in a page struct */
--
2.17.1
next prev parent reply other threads:[~2019-02-28 2:18 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-28 2:18 [PATCH 00/12] introduce percpu block scan_hint Dennis Zhou
2019-02-28 2:18 ` [PATCH 01/12] percpu: update free path with correct new free region Dennis Zhou
2019-03-02 12:56 ` Peng Fan
2019-02-28 2:18 ` [PATCH 02/12] percpu: do not search past bitmap when allocating an area Dennis Zhou
2019-03-02 13:32 ` Peng Fan
2019-03-02 22:23 ` Dennis Zhou
2019-03-03 8:41 ` Peng Fan
2019-02-28 2:18 ` [PATCH 03/12] percpu: introduce helper to determine if two regions overlap Dennis Zhou
2019-03-02 13:37 ` Peng Fan
2019-03-02 22:24 ` Dennis Zhou
2019-02-28 2:18 ` Dennis Zhou [this message]
2019-03-02 13:48 ` [PATCH 04/12] percpu: manage chunks based on contig_bits instead of free_bytes Peng Fan
2019-03-02 22:32 ` Dennis Zhou
2019-03-03 8:42 ` Peng Fan
2019-02-28 2:18 ` [PATCH 05/12] percpu: relegate chunks unusable when failing small allocations Dennis Zhou
2019-03-02 13:55 ` Peng Fan
2019-03-02 22:34 ` Dennis Zhou
2019-02-28 2:18 ` [PATCH 06/12] percpu: set PCPU_BITMAP_BLOCK_SIZE to PAGE_SIZE Dennis Zhou
2019-03-03 4:56 ` Peng Fan
2019-02-28 2:18 ` [PATCH 07/12] percpu: add block level scan_hint Dennis Zhou
2019-03-03 6:01 ` Peng Fan
2019-03-03 20:23 ` Dennis Zhou
2019-03-04 9:36 ` Peng Fan
2019-02-28 2:18 ` [PATCH 08/12] percpu: remember largest area skipped during allocation Dennis Zhou
2019-02-28 2:18 ` [PATCH 09/12] percpu: use block scan_hint to only scan forward Dennis Zhou
2019-02-28 2:18 ` [PATCH 10/12] percpu: make pcpu_block_md generic Dennis Zhou
2019-03-03 6:35 ` Peng Fan
2019-02-28 2:18 ` [PATCH 11/12] percpu: convert chunk hints to be based on pcpu_block_md Dennis Zhou
2019-03-03 8:18 ` Peng Fan
2019-03-03 20:22 ` Dennis Zhou
2019-03-04 6:36 ` Peng Fan
2019-02-28 2:18 ` [PATCH 12/12] percpu: use chunk scan_hint to skip some scanning Dennis Zhou
2019-03-03 8:38 ` Peng Fan
2019-02-28 14:47 ` [PATCH 00/12] introduce percpu block scan_hint Vlad Buslov
2019-03-13 20:19 ` Dennis Zhou
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=20190228021839.55779-5-dennis@kernel.org \
--to=dennis@kernel.org \
--cc=cl@linux.com \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=tj@kernel.org \
--cc=vladbu@mellanox.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).