I've built and tested 4.15 and the latest 4.18 with the following configs: CONFIG_PAGE_POISONING=y CONFIG_PAGE_POISONING_ZERO=y CONFIG_PAGE_POISONING_NO_SANITY=y
Attached is a libreoffice spreadsheet with the test results comparing kernels without the config, with the config and with the config with page_poison=1 for the 4.18 and 4.15 kernels. I ran nearly 200 stress-ng stress tests and gathered the throughput (based on bogo ops per second on the usr+sys time consumed) for each stress test. Each of the stress tests were run for 60 seconds on an idle 8 thread Xeon i7-3770. The bogo-ops data was then normalized against the kernel that didn't have the config changes. The data to look at is the geometric means of all the normalized test results: 4.18 kernel, geometric mean of normalized bogo/ops throughput: No page poisoning: 1.000 Config page poisoning: 1.003 Config page poionsing + page_poison=1: 0.991 4.15 kernel, geometric mean of normalized bogo/ops throughput: No page poisoning: 1.000 Config page poisoning: 1.025 Config page poionsing + page_poison=1: 0.977 where > 1.000 shows more throughput and < 1.000 shows degraded throughput So it appears that enabling page poisoning configs does not degrade performance and setting page_poison=1 degrades performance by a very small amount. ** Attachment added: "libreoffice spreadsheet with test results data" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1783651/+attachment/5170997/+files/kernel-poison-page-analysis.ods ** Changed in: linux (Ubuntu Cosmic) Assignee: Colin Ian King (colin-king) => (unassigned) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1783651 Title: Please enable CONFIG_PAGE_POISONING Status in linux package in Ubuntu: Confirmed Status in linux source package in Cosmic: Confirmed Bug description: I'd like to be able to use page poisoning, but CONFIG_PAGE_POISONING is not enabled on Ubuntu. (This option itself has a near-zero performance impact since it must be combined with the boot option "page_poison=1" to actually enable the poisoning.) To make the poisoning (when enabled) less of an impact, I'd also like to see CONFIG_PAGE_POISONING_ZERO=y too, which means GFP_ZEROing can be skipped. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1783651/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
