From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TQvig-0002uX-HO for ltp-list@lists.sourceforge.net; Wed, 24 Oct 2012 07:49:42 +0000 Received: from mx3-phx2.redhat.com ([209.132.183.24]) by sog-mx-3.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1TQvia-0005ej-PM for ltp-list@lists.sourceforge.net; Wed, 24 Oct 2012 07:49:42 +0000 Date: Wed, 24 Oct 2012 03:49:28 -0400 (EDT) From: Jan Stancek Message-ID: <1701010771.5419513.1351064968870.JavaMail.root@redhat.com> In-Reply-To: <508792B4.1050101@cn.fujitsu.com> MIME-Version: 1.0 Subject: Re: [LTP] Regarding shmat01 syscall test 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: gaowanlong@cn.fujitsu.com Cc: ltp-list@lists.sourceforge.net ----- Original Message ----- > From: "Wanlong Gao" > To: "Jan Stancek" > Cc: ltp-list@lists.sourceforge.net, "Om Prakash PAL" > Sent: Wednesday, 24 October, 2012 9:03:16 AM > Subject: Re: [LTP] Regarding shmat01 syscall test > > On 10/24/2012 02:43 PM, Jan Stancek wrote: > > > > > > ----- Original Message ----- > >> From: "Wanlong Gao" > >> To: "Om Prakash PAL" > >> Cc: ltp-list@lists.sourceforge.net > >> Sent: Wednesday, 24 October, 2012 2:45:47 AM > >> Subject: Re: [LTP] Regarding shmat01 syscall test > >> > >> On 10/23/2012 06:05 PM, Om Prakash PAL wrote: > >>> > >>> > >>> -----Original Message----- > >>> From: Wanlong Gao [mailto:gaowanlong@cn.fujitsu.com] > >>> Sent: Tuesday, October 23, 2012 3:07 PM > >>> To: Om Prakash PAL > >>> Cc: ltp-list@lists.sourceforge.net > >>> Subject: Re: [LTP] Regarding shmat01 syscall test > >>> > >>> On 10/23/2012 05:24 PM, Om Prakash PAL wrote: > >>>> Hi, > >>>> > >>>> I am working on syscall test: shmat01.c > >>>> > >>>> I have some confusion: > >>>> > >>>> > >>>> > >>>> In setup() : it is allocating shared memory by shmget() and > >>>> then > >>>> attaching by shmat() and after that detaching the attached > >>>> address (i.e. shmdt()) > >>>> > >>>> > >>>> > >>>> if (shmdt((const void *)base_addr) == -1) { > >>>> > >>>> tst_brkm(TBROK, cleanup, "Couldn't detach shared > >>>> memory"); > >>>> > >>>> } > >>>> > >>>> > >>>> > >>>> And again in main function it is using same "base_addr" as > >>>> attaching address, > >>>> > >>>> > >>>> > >>>> addr = shmat(*(TC[i].shmid), base_addr+TC[i].offset, > >>>> > >>>> TC[i].flags); > >>>> > >>>> how can we ensure(100%) that base_addr (virtual) will be free > >>>> till > >>>> this point for attaching?. > >>> > >>> Maybe we can't, but I didn't see any fail on this. Did you see > >>> any > >>> testing failure here? > >>> > >>> Yes, I got some failure and the reason of failure is : the > >>> address > >>> at which we want to attach is busy. > >> > >> OK, please feel free to send a patch, or can you tell us how to > >> reproduce it? > > > > I recall I could reproduce it, if I added single printf: > > http://article.gmane.org/gmane.linux.ltp/16480 > > Do you get a solution? Send out a patch? No, I haven't send any patch. About solution: I'm thinking, that instead of probing with shmat, we can mmap large chunk of memory, and then set base_addr somewhere in the middle and unmap the chunk. That is, using address that get_unmapped_area() is unlikely to pick. Regards, Jan > > > Thanks, > Wanlong Gao > > > > > Regards, > > Jan > > > > ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Ltp-list mailing list Ltp-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ltp-list