Message-ID: <4016BFD4.2040407@cosmosbay.com>
Date: Tue, 27 Jan 2004 20:45:24 +0100
From: dada1 <dada1@cosmosbay.com>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6) Gecko/20040113
MIME-Version: 1.0
To: Andi Kleen <ak@suse.de>
CC: linux-kernel@vger.kernel.org
Subject: Re: linux-2.6.1 x86_64 : STACK_TOP and text/data
References: <OFCE30A640.024A04A1-ONC1256E28.003023EA-C1256E28.0030BF4E@de.ibm.com.suse.lists.linux.kernel>	<40162E9A.1080005@cosmosbay.com.suse.lists.linux.kernel>	<p73k73dfdvs.fsf@nielsen.suse.de>	<4016B493.9050404@cosmosbay.com> <20040127202930.6c29bbcf.ak@suse.de>
In-Reply-To: <20040127202930.6c29bbcf.ak@suse.de>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 928
Lines: 37

Andi Kleen wrote:

>
>You're right. Thanks for reporting this. This seems to be a 2.6 
>specific bug, it didn't happen in 2.4.
>
>I will fix it. It should definitely use PAGE_OFFSET for 64bit 
>processes and 4GB for !3GB 32bit processes.
>
>-Andi
>
>
>  
>
Another thing I noticed in last glibc CVS (nptl)

Thread stacks are also allocated in the 1GB quadrant :

nptl/sysdeps/x86_64/pthreaddef.h
/* We prefer to have the stack allocated in the low 4GB since this
   allows faster context switches.  */      
#define ARCH_MAP_FLAGS MAP_32BIT 

Is this really true ?
Is memory allocated in the low 4GB is faster on x86_64  (64bit kernel, 
64 bit user prog ?)

Thank you

Eric Dumazet


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