From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Luck Date: Mon, 09 May 2011 23:08:44 +0000 Subject: Re: [PATCH] Don't mlock guardpage if the stack is growing up Message-Id: List-Id: References: <1304979549.4865.56.camel@mulgrave.site> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linus Torvalds Cc: James Bottomley , Mikulas Patocka , Fenghua Yu , Hugh Dickins , linux-kernel@vger.kernel.org, linux-parisc@vger.kernel.org, Michel Lespinasse , Oleg Nesterov , linux-ia64@vger.kernel.org On Mon, May 9, 2011 at 3:58 PM, Linus Torvalds wrote: > Ahh, so you never actually have one single mapping that has both flags set? > > In that case, I won't even worry about it. Definitely not for normal processes - I'm not sure how both stacks are set up for threads. > One thing I did want to verify: did the mlockall() actually change the > stack size without that patch? Just to double-check that the patch > actually did change semantics visibly. On an unpatched system I see this (lots more than one page of growth - pages are 64K on this config): 6007fffffff50000-6007fffffff70000 rw-p 00000000 00:00 0 6007fffffff50000-6008000000750000 rw-p 00000000 00:00 0 On a patched system I see (this one has 16K pages - no growth) 600007ffff9d0000-600007ffff9d4000 rw-p 00000000 00:00 0 600007ffff9d0000-600007ffff9d4000 rw-p 00000000 00:00 0 -Tony