> Nadia Derbey wrote: > > Andrew Morton wrote: > > > >> On Mon, 11 Feb 2008 15:16:47 +0100 [EMAIL PROTECTED] wrote: > >> > >> > >>> [PATCH 01/08] > >>> > >>> This patch computes msg_ctlmni to make it scale with the amount of > >>> lowmem. > >>> msg_ctlmni is now set to make the message queues occupy 1/32 of the > >>> available > >>> lowmem. > >>> > >>> Some cleaning has also been done for the MSGPOOL constant: the msgctl > >>> man page > >>> says it's not used, but it also defines it as a size in bytes (the code > >>> expresses it in Kbytes). > >>> > >> > >> > >> Something's wrong here. Running LTP's msgctl08 (specifically: > >> ltp-full-20070228) cripples the machine. It's a 4-way 4GB x86_64. > >> > >> http://userweb.kernel.org/~akpm/config-x.txt > >> http://userweb.kernel.org/~akpm/dmesg-x.txt > >> > >> Normally msgctl08 will complete in a second or two. With this patch I > >> don't know how long it will take to complete, and the machine is horridly > >> bogged down. It does recover if you manage to kill msgctl08. Feels like > >> a terrible memory shortage, but there's plenty of memory free and it > >> isn't > >> swapping. > >> > >> > >> > > > > Before the patchset, msgctl08 used to be run with the old msgmni value: > > 16. Now it is run with a much higher msgmni value (1746 in my case), > > since it scales to the memory size. > > When I call "msgctl08 100000 16" it completes fast. > > > > Doing the follwing on the ref kernel: > > echo 1746 > /proc/sys/kernel/msgmni > > msgctl08 100000 1746 > > > > makes th test block too :-( > > > > Will check to see where the problem comes from. > > > > Well, actually, the test does not block, it only takes much much more > time to be executed: > > doing this: > date; ./msgctl08 100000 XXX; date > > > gives us the following results: > XXX 16 32 64 128 256 512 1024 1746 > time(secs) 2 4 8 16 32 64 132 241 > > XXX is the # of msg queues to be created = # of processes to be forked > as readers = # of processes to be created as writers > time is approximative since it is obtained by a "date" before and after. > > XXX used to be 16 before the patchset ---> 1st column > --> 16 processes forked as reader > --> + 16 processes forked as writers > --> + 16 msg queues > XXX = 1746 (on my victim) after the patchset ---> last column > --> 1746 reader processes forked > --> + 1746 writers forked > --> + 1746 msg queues created > > The same tests on the ref kernel give approximatly the same results. > > So if we don't want this longer time to appear as a regression, the LTP > should be changed: > 1) either by setting the result of get_max_msgqueues() as the MSGMNI > constant (16) (that would be the best solution in my mind) > 2) or by warning the tester that it may take a long time to finish. > > There would be 3 tests impacted: > > kernel/syscalls/ipc/msgctl/msgctl08.c > kernel/syscalls/ipc/msgctl/msgctl09.c > kernel/syscalls/ipc/msgget/msgget03.c
We will change the test case if need that be. Nadia, kindly send us the patch set which will do the necessary changes. Regards-- Subrata > > Cc-ing ltp mailing list ... > > Regards, > Nadia > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > _______________________________________________ > Ltp-list mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/ltp-list -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
