lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1422309132-28030-1-git-send-email-rogachevsergei@gmail.com>
Date:	Tue, 27 Jan 2015 00:52:11 +0300
From:	Sergei Rogachev <rogachevsergei@...il.com>
To:	akpm@...ux-foundation.org, iamjoonsoo.kim@....com
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Sergei Rogachev <rogachevsergei@...il.com>
Subject: [PATCH 0/1] mm/page_ext: remove unnecessary stack_trace field

The functionality named "page owner" has resurrected the structure page_ext
which is used for keeping additional page-related information. Every page in
the system has its own corresponding page_ext structure.

Page owner uses this structure to keep allocation order, gfp_mask and backtrace
entries; moreover page_ext includes a field of type "struct stack_trace". And
this field is used for collecting backtraces: a pointer to struct stack_trace is
passed to save_stack_trace in the function __set_page_owner. But it is really
not necessary to keep dedicated stack_trace structures for all physical pages in
the system, only an amount of saved backtrace entries is needed to be saved.

The stack_trace structure can be allocated on the stack (it is relatively small)
and used for save_stack_trace invocation. Such change can save 12 bytes of
memory per page if page owner functionality is enabled.

Sergei Rogachev (1):
  mm/page_ext: remove unnecessary stack_trace field

 include/linux/page_ext.h |  2 +-
 mm/page_owner.c          | 21 ++++++++++++---------
 2 files changed, 13 insertions(+), 10 deletions(-)

-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ