On Tue, Feb 02, 2016 at 03:59:50PM +0200, Kirill A. Shutemov wrote: > On Mon, Jan 25, 2016 at 04:46:58PM +0000, Hugh Greenberg wrote: > > Kirill A. Shutemov <kirill <at> shutemov.name> writes: > > > > > > > > On Sat, Jan 23, 2016 at 03:57:21PM +0000, Hugh Greenberg wrote: > > > > Kirill A. Shutemov <kirill <at> shutemov.name> writes: > > > > > > > > > > Could you try to insert > > "late_initcall(set_recommended_min_free_kbytes);" > > > > > back and check if makes any difference. > > > > > > > > > > > > > We tested adding late_initcall(set_recommended_min_free_kbytes); > > > > back in 4.1.14 and it made a huge difference. We aren't sure if the > > > > issue is 100% fixed, but it could be. We will keep testing it. > > > > > > It would be nice to have values of min_free_kbytes before and after > > > set_recommended_min_free_kbytes() in your configuration. > > > > > > > Before adding set_recommended_min_free_kbytes: 5391 > > After: 67584 > > [ add more people to the thread ] > > The 'before' value look low to me for machine with 2G of RAM. > > In the bugzilla[1], you've mentioned zram. I wounder if we need to > increase min_free_kbytes when zram is in use as we do for THP. > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=110501 Normally, it's recommended to increate min_free_kbytes when zram is used for swap because zram should allocate a page in reclaim path dynamically to keep compressed page. However, when I read bugzilla's perf profile, I can't find any zram related things and if there is lack of free memory for zram page allocation due to changing min_free_kbytes, user will see below error message. pr_err("Error allocating memory for compressed page: %u, size=%zu\n" -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>