From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1VCOu7-0003fs-Tr for ltp-list@lists.sourceforge.net; Thu, 22 Aug 2013 07:01:59 +0000 Received: from mx3-phx2.redhat.com ([209.132.183.24]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1VCOu6-0001LM-CT for ltp-list@lists.sourceforge.net; Thu, 22 Aug 2013 07:01:59 +0000 Date: Thu, 22 Aug 2013 03:01:52 -0400 (EDT) From: Jan Stancek Message-ID: <1462085563.2226697.1377154912029.JavaMail.root@redhat.com> In-Reply-To: <5215AC0E.6000205@oracle.com> References: <52122141.3020005@oracle.com> <1377086098-32691-3-git-send-email-stanislav.kholmanskikh@oracle.com> <212598736.1836601.1377088154292.JavaMail.root@redhat.com> <5214BEFC.504@oracle.com> <1748281355.1930512.1377095285040.JavaMail.root@redhat.com> <5215AC0E.6000205@oracle.com> MIME-Version: 1.0 Subject: Re: [LTP] [PATCH V2 3/3] lib/numa_helper.c: fix nodemask_size List-Id: Linux Test Project General Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-list-bounces@lists.sourceforge.net To: Stanislav Kholmanskikh Cc: vasily isaenko , ltp-list@lists.sourceforge.net ----- Original Message ----- > From: "Stanislav Kholmanskikh" > To: "Jan Stancek" > Cc: ltp-list@lists.sourceforge.net, "vasily isaenko" > Sent: Thursday, 22 August, 2013 8:13:34 AM > Subject: Re: [PATCH V2 3/3] lib/numa_helper.c: fix nodemask_size > I think we cannot clear area by zeroing only few bytes of a long. Each > byte of a long should > be zeroed. Agreed, that was good point. > >> This formula may give incorrect results. For example, if max_mode = 66 > >> and sizeof(long) = 8, then > >> ALIGN(max_node / 8, sizeof(long)) will output 8 and we will lost 2 bits. > >> The correct output should be 16. > >> > >> I think as max_node contains number of bits so we should align it on > >> sizeof(long)*8 boundary and after that divide the final result by 8. > > Agreed, we should align on bits then divide. > > > > What if we align max_node? Then we can be sure that nodemask_size > > in all functions is also aligned: > Ok. And for convenience the same for migrate_pages fix ? I'll leave it up to you. Man page says, that "bits beyond those specified by maxnode are ignored" so both ways should work equally well in those testcases. Regards, Jan > > > > > > diff --git a/testcases/kernel/lib/numa_helper.c > > b/testcases/kernel/lib/numa_helper.c > > index 4157816..a2b6b4a 100644 > > --- a/testcases/kernel/lib/numa_helper.c > > +++ b/testcases/kernel/lib/numa_helper.c > > @@ -60,7 +60,7 @@ unsigned long get_max_node(void) > > #if HAVE_NUMA_H > > static void get_nodemask_allnodes(nodemask_t * nodemask, unsigned long > > max_node) > > { > > - unsigned long nodemask_size = max_node / 8 + 1; > > + unsigned long nodemask_size = max_node / 8; > > int i; > > char fn[64]; > > struct stat st; > > @@ -76,7 +76,7 @@ static void get_nodemask_allnodes(nodemask_t * nodemask, > > unsigned long max_node) > > static int filter_nodemask_mem(nodemask_t * nodemask, unsigned long > > max_node) > > { > > #if MPOL_F_MEMS_ALLOWED > > - unsigned long nodemask_size = max_node / 8 + 1; > > + unsigned long nodemask_size = max_node / 8; > > memset(nodemask, 0, nodemask_size); > > /* > > * avoid numa_get_mems_allowed(), because of bug in getpol() > > @@ -164,8 +164,8 @@ int get_allowed_nodes_arr(int flag, int *num_nodes, int > > **nodes) > > *nodes = NULL; > > > > #if HAVE_NUMA_H > > - unsigned long max_node = get_max_node(); > > - unsigned long nodemask_size = max_node / 8 + 1; > > + unsigned long max_node = ALIGN(get_max_node(), sizeof(long)*8); > > + unsigned long nodemask_size = max_node / 8; > > > > nodemask = malloc(nodemask_size); > > if (nodes) > > > > Regards, > > Jan > > ------------------------------------------------------------------------------ Introducing Performance Central, a new site from SourceForge and AppDynamics. Performance Central is your source for news, insights, analysis and resources for efficient Application Performance Management. Visit us today! http://pubads.g.doubleclick.net/gampad/clk?id=48897511&iu=/4140/ostg.clktrk _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list