linux-kernel - Re: [RFC][PATCH 5/8] RSS controller task migration support

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: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20061115115937.B0A851B6A2@openx4.frec.bull.fr>
Date:	Wed, 15 Nov 2006 12:59:37 +0100 (CET)
From:	Patrick.Le-Dot@...l.net (Patrick.Le-Dot)
To:	balbir@...ibm.com
Cc:	ckrm-tech@...ts.sourceforge.net, dev@...nvz.org,
	haveblue@...ibm.com, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, rohitseth@...gle.com
Subject: Re: [RFC][PATCH 5/8] RSS controller task migration support

Hi Balbir,

The get_task_mm()/mmput(mm) usage is not correct.
With CONFIG_DEBUG_SPINLOCK_SLEEP=y :

BUG: sleeping function called from invalid context at kernel/fork.c:390
in_atomic():1, irqs_disabled():0
 [<c0116620>] __might_sleep+0x97/0x9c
 [<c0116a2e>] mmput+0x15/0x8b
 [<c01582f6>] install_arg_page+0x72/0xa9
 [<c01584b1>] setup_arg_pages+0x184/0x1a5
 ...

BUG: sleeping function called from invalid context at kernel/fork.c:390
in_atomic():1, irqs_disabled():0
 [<c0116620>] __might_sleep+0x97/0x9c
 [<c0116a2e>] mmput+0x15/0x8b
 [<c01468ee>] do_no_page+0x255/0x2bd
 [<c0146b8d>] __handle_mm_fault+0xed/0x1ef
 [<c0111884>] do_page_fault+0x247/0x506
 [<c011163d>] do_page_fault+0x0/0x506
 [<c0348f99>] error_code+0x39/0x40

current->mm seems to be enough here.

In patch4, memctlr_dec_rss(page, mm) should be memctlr_dec_rss(page)
to compile correctly.

and in patch0 :
> 4. Disable cpuset's (to simply assignment of tasks to resource groups)
>         cd /container
>         echo 0 > cpuset_enabled

should be :
        echo 0 > cpuacct_enabled

Note : cpuacct_enabled is 0 by default.

Now the big question : to implement guarantee, the LRU needs to know
if a page can be removed from memory or not.
Any ideas to do that without any change in the struct page ?

Patrick

+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+    Patrick Le Dot
 mailto: P@...ck.Le-Dot@...l.net         Centre UNIX de BULL SAS
 Phone : +33 4 76 29 73 20               1, Rue de Provence     BP 208
 Fax   : +33 4 76 29 76 00               38130 ECHIROLLES Cedex FRANCE
 Bull, Architect of an Open World TM
 www.bull.com
-
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/