Hello, On Mon, Jan 25, 2016 at 11:04:18AM +0800, kernel test robot wrote: > FYI, we noticed the below changes on > > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > commit 40e318e509d2c9f3cdb00ef32d2c14b9868af16b ("ksm: introduce > ksm_max_page_sharing per page deduplication limit") > > We found LKP KSM test case failed for your patch. > > ========================================================================================= > compiler/kconfig/rootfs/tbox_group/test/testcase: > > gcc-5/x86_64-nfsroot/debian-x86_64-2015-02-07.cgz/vm-lkp-wsx03-4G/mm_functional_positive/otc_kernel_qa-ts_ltp_ddt > > commit: > 77505a33e539477f1fbe5e6136df5b265f39cccf > 40e318e509d2c9f3cdb00ef32d2c14b9868af16b > > 77505a33e539477f 40e318e509d2c9f3cdb00ef32d > ---------------- -------------------------- > fail:runs %reproduction fail:runs > | | | > :4 100% 4:4 > otc_kernel_qa-ts_ltp_ddt.ksm01.fail > :4 100% 4:4 > otc_kernel_qa-ts_ltp_ddt.ksm01_1.fail
In this case it's one rare case of false positive. The change in the merging levels is a "feature" not a "bug". LTP validation math on ksm sysfs levels shall be updated to account for the runtime value of /sys/kernel/mm/ksm/max_page_sharing which in turn affects pages_sharing/pages_shared. In fact you could add validation for the new fields like stable_node_dups and stable_node_chains on top of the existing verifications on pages_shar*. For now you should re-run the test after: echo 2 >/sys/kernel/mm/ksm/run echo 10000000 > /sys/kernel/mm/ksm/max_page_sharing echo 1 >/sys/kernel/mm/ksm/run And then LTP will pass as usual. Thanks for the greatly valuable regression testing work, Andrea