From: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Date: Fri, 25 Apr 2008 14:13:09 +0000 (+0900)
Subject: [IA64] bugfix: nptcg breaks cpu-hotadd
X-Git-Tag: v2.6.26-rc1~348^2~3
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e617fce64e5faea149fcf3bffc1b42e4ba29e7e5;p=linux-2.6

[IA64] bugfix: nptcg breaks cpu-hotadd

If "max_purges" from PAL is 0, it actually means 1.

However it was not handled later when a hot-added cpu pass the
max_purges from PAL.  This makes systems easy to go BUG_ON().

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---

diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index d52ec4e834..8caf42471f 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -168,7 +168,10 @@ setup_ptcg_sem(int max_purges, int nptcg_from)
 	static int firstcpu = 1;
 
 	if (toolatetochangeptcgsem) {
-		BUG_ON(max_purges < nptcg);
+		if (nptcg_from == NPTCG_FROM_PAL && max_purges == 0)
+			BUG_ON(1 < nptcg);
+		else
+			BUG_ON(max_purges < nptcg);
 		return;
 	}