From c07d14deb549f76ef59dd1085ca73c38537ea73e Mon Sep 17 00:00:00 2001 From: Baptiste Daroussin Date: Wed, 15 Nov 2017 12:48:36 +0000 Subject: [PATCH] remove the poor emulation of the IllumOS needfree global variable to prevent the ARC reclaim thread running longer than needed. Update the arc::needfree dtrace probe triggered in arc_lowmem() to also report the value we may want to free. Submitted by: Nikita Kozlov Reviewed by: avg Approved by: avg MFC after: 3 weeks Sponsored by: blade Differential Revision: https://reviews.freebsd.org/D12163 --- .../opensolaris/uts/common/fs/zfs/arc.c | 20 +------------------ 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c index 92d8b41c24ac..209b33f16347 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c @@ -4199,8 +4199,6 @@ arc_shrink(int64_t to_free) } } -static long needfree = 0; - typedef enum free_memory_reason_t { FMR_UNKNOWN, FMR_NEEDFREE, @@ -4238,14 +4236,6 @@ arc_available_memory(void) free_memory_reason_t r = FMR_UNKNOWN; #ifdef _KERNEL - if (needfree > 0) { - n = PAGESIZE * (-needfree); - if (n < lowest) { - lowest = n; - r = FMR_NEEDFREE; - } - } - /* * Cooperate with pagedaemon when it's time for it to scan * and reclaim some pages. @@ -4510,9 +4500,6 @@ arc_reclaim_thread(void *dummy __unused) int64_t to_free = (arc_c >> arc_shrink_shift) - free_memory; if (to_free > 0) { -#ifdef _KERNEL - to_free = MAX(to_free, ptob(needfree)); -#endif arc_shrink(to_free); } } else if (free_memory < arc_c >> arc_no_grow_shift) { @@ -4533,9 +4520,6 @@ arc_reclaim_thread(void *dummy __unused) * infinite loop. */ if (arc_size <= arc_c || evicted == 0) { -#ifdef _KERNEL - needfree = 0; -#endif /* * We're either no longer overflowing, or we * can't evict anything more, so we should wake @@ -6310,9 +6294,7 @@ arc_lowmem(void *arg __unused, int howto __unused) { mutex_enter(&arc_reclaim_lock); - /* XXX: Memory deficit should be passed as argument. */ - needfree = btoc(arc_c >> arc_shrink_shift); - DTRACE_PROBE(arc__needfree); + DTRACE_PROBE1(arc__needfree, int64_t, ((int64_t)freemem - zfs_arc_free_target) * PAGESIZE); cv_signal(&arc_reclaim_thread_cv); /*