From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: [PATCH 1 of 3] xentrace: correct formula to calculate t_info_pages Date: Wed, 30 Mar 2011 20:04:33 +0200 Message-ID: <8a2ce5e49b2c5f2e0137.1301508273@localhost> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: George Dunlap List-Id: xen-devel@lists.xenproject.org # HG changeset patch # User Olaf Hering # Date 1301423840 -7200 # Node ID 8a2ce5e49b2c5f2e013734b5d53eae37572f4101 # Parent 45eeeb6d0481efaab2a59941e1b8e061aead37d4 xentrace: correct formula to calculate t_info_pages The current formula to calculate t_info_pages, based on the initial code, is slightly incorrect. It may allocate more than needed. Each cpu has some pages/mfns stored as uint32_t. That list is stored with an offset at tinfo. Signed-off-by: Olaf Hering --- xen/common/trace.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff -r 45eeeb6d0481 -r 8a2ce5e49b2c xen/common/trace.c --- a/xen/common/trace.c Tue Mar 29 16:34:01 2011 +0100 +++ b/xen/common/trace.c Tue Mar 29 20:37:20 2011 +0200 @@ -110,7 +110,7 @@ { struct t_buf dummy; typeof(dummy.prod) size; - unsigned int t_info_words, t_info_bytes; + unsigned int t_info_words; /* force maximum value for an unsigned type */ size = -1; @@ -125,9 +125,8 @@ pages = size; } - t_info_words = num_online_cpus() * pages + t_info_first_offset; - t_info_bytes = t_info_words * sizeof(uint32_t); - t_info_pages = PFN_UP(t_info_bytes); + t_info_words = num_online_cpus() * pages * sizeof(uint32_t); + t_info_pages = PFN_UP(t_info_first_offset + t_info_words); printk(XENLOG_INFO "xentrace: requesting %u t_info pages " "for %u trace pages on %u cpus\n", t_info_pages, pages, num_online_cpus());