From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Ub7zK-00079X-4R for ltp-list@lists.sourceforge.net; Sat, 11 May 2013 11:29:18 +0000 Received: from [222.73.24.84] (helo=song.cn.fujitsu.com) by sog-mx-2.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1Ub7zG-0004Rz-03 for ltp-list@lists.sourceforge.net; Sat, 11 May 2013 11:29:18 +0000 Message-ID: <518E2B58.3020608@cn.fujitsu.com> Date: Sat, 11 May 2013 19:28:24 +0800 From: Wanlong Gao MIME-Version: 1.0 References: <83efca15b955541cfdd6a0d7a07bd303381e5ed4.1368177082.git.zliu@redhat.com> <518CC158.20108@cn.fujitsu.com> <1293337679.9710631.1368181080556.JavaMail.root@redhat.com> In-Reply-To: <1293337679.9710631.1368181080556.JavaMail.root@redhat.com> Subject: Re: [LTP] [PATCH 1/3] mm/ksm: set the merge_across_nodes knob before testing Reply-To: gaowanlong@cn.fujitsu.com 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: Zhouping Liu Cc: LTP List On 05/10/2013 06:18 PM, Zhouping Liu wrote: > Hi Wanlong, > > ----- Original Message ----- >> From: "Wanlong Gao" >> To: "Zhouping Liu" >> Cc: "LTP List" >> Sent: Friday, May 10, 2013 5:43:52 PM >> Subject: Re: [LTP] [PATCH 1/3] mm/ksm: set the merge_across_nodes knob before testing >> >> On 05/10/2013 05:13 PM, Zhouping Liu wrote: >>> This kernel commit 90bd6fd31c809(ksm: allow trees per NUMA node) >>> introduced a new KSM sysfs knob /sys/kernel/mm/ksm/merge_across_nodes, >>> when it is set to zero, only pages from the same node are merged, >>> which is different with the previous behavior, and ksm test cases >>> sometimes will fail in NUMA system. >>> >>> Signed-off-by: Zhouping Liu >> >> While how about wrap the set and reset "merge_across_nodes" value to >> functions, >> so that we can reduce the dup code and dup comments? > > yeah, it sounds good, but... look at the codes again: > > ... > void cleanup(void) > { > + if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) > + /* recover the old value */ > + SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", > + "%d", merge_across_nodes); > > resetting "merge_across_nodes" only needs one statement. > > + > umount_mem(CPATH, CPATH_NEW); > TEST_CLEANUP; > } > @@ -136,6 +143,16 @@ void setup(void) > if (access(PATH_KSM, F_OK) == -1) > tst_brkm(TCONF, NULL, "KSM configuration is not enabled"); > > + if (access(PATH_KSM "merge_across_nodes", F_OK) == 0) { > + /* > + * Save the current value of merge_across_nodes knob, > + * and make it perform as the default behavior. > + */ > + SAFE_FILE_SCANF(NULL, PATH_KSM "merge_across_nodes", > + "%d", &merge_across_nodes); > + SAFE_FILE_PRINTF(NULL, PATH_KSM "merge_across_nodes", "1"); > > and setting the value only needs three statements, and it looks easy to understand, > I can remove the comments from ksm02.c ksm03.c ksm04.c to reduce the duplicated comments. > > also "merge_across_nodes" is a long string, I can't think of a better function name to > implement set/unset merge_across_nodes, so... IMO, the current codes is good, do you think so? OK to me. Thanks, Wanlong Gao > > + } > + > ... > > ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list