linux-kernel - Re: [PATCH] Memory management livelock

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

Message-Id: <200810031429.10040.nickpiggin@yahoo.com.au>
Date:	Fri, 3 Oct 2008 14:29:09 +1000
From:	Nick Piggin <nickpiggin@...oo.com.au>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Mikulas Patocka <mpatocka@...hat.com>,
	linux-kernel@...r.kernel.org, linux-mm@...r.kernel.org,
	agk@...hat.com, mbroz@...hat.com, chris@...chsys.com
Subject: Re: [PATCH] Memory management livelock

On Friday 03 October 2008 14:17, Andrew Morton wrote:
> On Fri, 3 Oct 2008 14:07:55 +1000 Nick Piggin <nickpiggin@...oo.com.au> 
> > Possibly a new mutex in the address_space?
>
> That's another, umm 24 bytes minimum in the address_space (and inode).
> That's fairly ouch, which is why Miklaus did that hokey bit-based
> thing.

Well yeah, it would be a bit based mutex in mapping->flags with
hashed waitqueues. Like Miklaus's.


> > Yeah... I went to break the sync/async cases into two, but it looks like
> > it may not have been worthwhile. Just another branch might be the best
> > way to go.
>
> Yup.  Could add another do-this flag in the writeback_control, perhaps.
> Or even a function pointer.

Yeah... possibly we could just _always_ do the PAGECACHE_TAG_FSYNC thing
if mode != WB_SYNC_NONE. I think if we had the infrastructure there to
do it all, it should always be something we want to do for data integrity
writeout.
--
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/