Date: Wed, 23 May 2012 11:05:14 -0700 From: Maksim Yevmenkin <maksim.yevmenkin@gmail.com> To: current@freebsd.org Subject: RFC: [PATCH] disabling buckets under "low memory" Message-ID: <CAFPOs6qihXPA_N7CbYHa=U_PMcKPazXEQy7c9xygUpVWmPzx1g@mail.gmail.com>
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hello,
would anyone object to the following patch?
===
Index: uma_core.c
===================================================================
--- uma_core.c (revision 616)
+++ uma_core.c (working copy)
@@ -267,10 +267,7 @@
static void
bucket_enable(void)
{
- if (cnt.v_free_count < cnt.v_free_min)
- bucketdisable = 1;
- else
- bucketdisable = 0;
+ bucketdisable = vm_page_count_min();
}
===
i've observed situation where per-cpu buckets were disabled while
there were enough free cached pages. basically, cnt.v_free_count was
sitting stable at a value lower than cnt.v_free_min and that caused
massive performance drop. tuning down vm.v_free_min sysctl immediately
helped.
thanks,
max
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