[Xen-devel] Bus error while allocating hugepages in domain 0

To:	Xen-devel <Xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject:	[Xen-devel] Bus error while allocating hugepages in domain 0
From:	Kaustubh Kabra <kaustubhwise@xxxxxxxxx>
Date:	Fri, 28 Jan 2011 02:07:52 +0530
Cc:
Delivery-date:	Thu, 27 Jan 2011 12:39:15 -0800
Dkim-signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:x-google-sender-delegation :date:x-google-sender-auth:message-id:subject:from:to:content-type; bh=BdCnNqhIJ22B1BgYqsDOJQLkJZwgyPB6P3QtraRDkaA=; b=C9eYP10rehz/QHPGFOcMueh8vkCa2MS/6YfXFCgkZbJ5h0XQWCb0jP5UjJPI45hUFa 90URrTYEjhmkOx4DzUA6MwCK9zOTRhWJ/R/oBM7FXs7inhr9EUeDO/QSNueFLBp1z3s+ eOzqqOBEI0qkKu41Ts/XQ8vPHAOWBKF5yOYmY=
Domainkey-signature:	a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:x-google-sender-delegation:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=aK8RPciDpthUmlDDZu8DwN9nLot5qjy9W4TiKSR3Jbd1kgYIDmEAC4vgN3OSkC6iE9 PwJUcLkSMNmrGB1s78a9neDjT1znlgKh5yvrOCmRxficA3/+clDmxRN8lAAmBwLY8oS0 8+ZX+aqGSgxwl2JvbptH4bllyAaUS4Cfhm6do=
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

Hi,

My dom 0 is jeremy kernel 2.6.32.27 with 3.5 GB allocated memory. I tried allocating 700 huge pages in domain 0 using-
]echo 700 > /proc/sys/vm/nr_hugepages

To verify -
]cat /proc/meminfo |grep Huge
HugePages_Total:     700
HugePages_Free:        0
HugePages_Rsvd:    18446744073709551019
HugePages_Surp:        0
Hugepagesize:       2048 kB

This memory information is not as per expectation.
Can anyone explain whether it has really allocated huge pages as calling mmap with MAP_HUGETLB using

]addr = mmap((void *)0x0UL,600UL*1024*1024 , PROT_WRITE,MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB , 0, 0);

also results into a bus error.

]dmesg-
Process 4617(a.out) has RLIMIT_CORE set to 0
Aborting core

]strace-
--- SIGBUS (Bus error) @ 0 (0) ---
+++ killed by SIGBUS +++
Bus error

--
Kaustubh Kabra

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

WARNING - OLD ARCHIVES

xen-devel

[Xen-devel] Bus error while allocating hugepages in domain 0