On 12.11.2006 [11:18:21 +1100], David Gibson wrote: > On Fri, Nov 10, 2006 at 11:39:40AM -0800, Nishanth Aravamudan wrote: > > On 03.11.2006 [11:52:26 +1100], David Gibson wrote: > > > Here are a pair of patches adding extra testcases for some of the > > > kernel bugs recently found by Hugh Dickins. These patches went to the > > > linux-mm list and some other people, but haven't made it to this list > > > yet, and appear to have dropped by the wayside. > > > > > > As extra testcase patches, these should both be low risk. > > > > Ok, I've noticed a problem with truncate_sigbus_versus_oom. On a G5 > > running 2.6.19-rc5, with 200 hugepages allocated, I get: > > > > truncate_sigbus_versus_oom 200 (32): FAIL mmap() reserving all pages > > truncate_sigbus_versus_oom 200 (64): ./run_tests.sh: line 30: 8482 > > Segmentation fault PATH="obj$BITS:$PATH" > > LD_LIBRARY_PATH="$LD_LIBRARY_PATH:../obj$BITS" $ENV "$@" > > > > But with only 100 hugepages allocated, I get: > > > > truncate_sigbus_versus_oom 100 (32): PASS > > truncate_sigbus_versus_oom 100 (64): PASS > > Ah, yes. In fact there are several testcases with this problem. The > 32-bit version fails because it attempts to consume all available > hugepages, but runs out of address space first. > > > Beyond the known truncate_above_4G issues, these are the only tests that > > fail on the G5 with 200 hugepages allocated. Should we constrain the > > maximum parameter sent to this test? > > No. If we constrain the parameter, we won't get the oom condition > that these tests require. What we need to do is to consume all the > pages without using all the address space. With a shared mapping > that's pretty easy: just map block of pages that will fit in the 32 > bit address space, then unmap them (they won't be discarded because > they're in the persistent hugetlbfs file), then map the next block > from an offset higher than the first block and so forth until all the > pages are consumed. > > I've been meaning to implement this, but have been chasing more > important bugs. Feel free to go for it...
Fair enough, I'll add this to my todo. Thanks, Nish -- Nishanth Aravamudan <[EMAIL PROTECTED]> IBM Linux Technology Center ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Libhugetlbfs-devel mailing list Libhugetlbfs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libhugetlbfs-devel
