From: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
To: Andrey Ryabinin <aryabinin@virtuozzo.com>,
Alexander Potapenko <glider@google.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: KASAN overhead?
Date: Fri, 18 Mar 2016 16:41:24 -0400 [thread overview]
Message-ID: <7300.1458333684@turing-police.cc.vt.edu> (raw)
[-- Attachment #1: Type: text/plain, Size: 2012 bytes --]
So I built linux-next next-20160417 with KASAN enabled:
CONFIG_KASAN_SHADOW_OFFSET=0xdffffc0000000000
CONFIG_HAVE_ARCH_KASAN=y
CONFIG_KASAN=y
# CONFIG_KASAN_OUTLINE is not set
CONFIG_KASAN_INLINE=y
CONFIG_TEST_KASAN=m
and saw an *amazing* slowdown. For comparison, here is the time taken
to reach various points in the dmesg:
% grep -i free dmesg.0317*
dmesg.0317:[ 1.560907] Freeing SMP alternatives memory: 28K (ffffffff93d3e000 - ffffffff93d45000)
dmesg.0317:[ 12.041550] Freeing initrd memory: 10432K (ffff88003f5cb000 - ffff88003fffb000)
dmesg.0317:[ 16.458451] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out
dmesg.0317:[ 16.545603] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out
dmesg.0317:[ 17.818934] Freeing unused kernel memory: 1628K (ffffffff93ba7000 - ffffffff93d3e000)
dmesg.0317:[ 17.820234] Freeing unused kernel memory: 1584K (ffff880012c74000 - ffff880012e00000)
dmesg.0317:[ 17.828426] Freeing unused kernel memory: 1524K (ffff880013483000 - ffff880013600000)
dmesg.0317-nokasan:[ 0.028821] Freeing SMP alternatives memory: 28K (ffffffffaf104000 - ffffffffaf10b000)
dmesg.0317-nokasan:[ 1.587232] Freeing initrd memory: 10432K (ffff88003f5cb000 - ffff88003fffb000)
dmesg.0317-nokasan:[ 2.433557] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out
dmesg.0317-nokasan:[ 2.439411] ata1.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out
dmesg.0317-nokasan:[ 2.488113] Freeing unused kernel memory: 1324K (ffffffffaefb9000 - ffffffffaf104000)
dmesg.0317-nokasan:[ 2.488518] Freeing unused kernel memory: 88K (ffff88002e9ea000 - ffff88002ea00000)
dmesg.0317-nokasan:[ 2.489490] Freeing unused kernel memory: 388K (ffff88002ed9f000 - ffff88002ee00000)
Only config difference was changing to CONFIG_KASAN=n.
Is this level of slowdown expected? Or is my kernel unexpectedly off in the weeds?
[-- Attachment #2: Type: application/pgp-signature, Size: 848 bytes --]
next reply other threads:[~2016-03-18 20:41 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-18 20:41 Valdis Kletnieks [this message]
2016-03-19 12:13 ` Alexander Potapenko
2016-03-20 1:14 ` Valdis.Kletnieks
2016-03-21 13:45 ` Alexander Potapenko
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=7300.1458333684@turing-police.cc.vt.edu \
--to=valdis.kletnieks@vt.edu \
--cc=aryabinin@virtuozzo.com \
--cc=glider@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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