Author: rstone Date: Thu Aug 20 20:28:51 2015 New Revision: 286970 URL: https://svnweb.freebsd.org/changeset/base/286970
Log: Prevent ticks rollover from preventing vm_lowmem event Currently vm_pageout_scan() uses a ticks-based scheme to rate-limit the number of times that the vm_lowmem event will happen. However if no events happen for long enough for ticks to roll over, this leaves us in a long window in which vm_lowmem events will not happen. Replace the use of ticks with time_t to prevent rollover from ever being an issue. Reviewed by: ian MFC after: 3 weeks Sponsored by: EMC / Isilon Storage Division Differential Revision: https://reviews.freebsd.org/D3439 Modified: head/sys/vm/vm_pageout.c Modified: head/sys/vm/vm_pageout.c ============================================================================== --- head/sys/vm/vm_pageout.c Thu Aug 20 19:39:15 2015 (r286969) +++ head/sys/vm/vm_pageout.c Thu Aug 20 20:28:51 2015 (r286970) @@ -93,6 +93,7 @@ __FBSDID("$FreeBSD$"); #include <sys/sdt.h> #include <sys/signalvar.h> #include <sys/smp.h> +#include <sys/time.h> #include <sys/vnode.h> #include <sys/vmmeter.h> #include <sys/rwlock.h> @@ -171,7 +172,7 @@ static int vm_pageout_update_period; static int defer_swap_pageouts; static int disable_swap_pageouts; static int lowmem_period = 10; -static int lowmem_ticks; +static time_t lowmem_uptime; #if defined(NO_SWAPPING) static int vm_swap_enabled = 0; @@ -1034,7 +1035,7 @@ vm_pageout_scan(struct vm_domain *vmd, i * some. We rate limit to avoid thrashing. */ if (vmd == &vm_dom[0] && pass > 0 && - (ticks - lowmem_ticks) / hz >= lowmem_period) { + (time_uptime - lowmem_uptime) >= lowmem_period) { /* * Decrease registered cache sizes. */ @@ -1045,7 +1046,7 @@ vm_pageout_scan(struct vm_domain *vmd, i * drained above. */ uma_reclaim(); - lowmem_ticks = ticks; + lowmem_uptime = time_uptime; } /* _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
