linux-kernel - [PATCH] hugetlb: Abort a hugepage pool resize if a signal is pending

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Message-ID: <20091202141504.GE1457@csn.ul.ie>
Date:	Wed, 2 Dec 2009 14:15:05 +0000
From:	Mel Gorman <mel@....ul.ie>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Dave Hansen <dave@...ux.vnet.ibm.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] hugetlb: Abort a hugepage pool resize if a signal is
	pending

If a user asks for a hugepage pool resize but specified a large number, the
machine can begin trashing. In response, they might hit ctrl-c but signals
are ignored and the pool resize continues until it fails an allocation. This
can take a considerable amount of time so this patch aborts a pool resize
if a signal is pending.

[dave@...ux.vnet.ibm.com: His idea]
Signed-off-by: Mel Gorman <mel@....ul.ie>
---
 mm/hugetlb.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index af02ee8..a952cb8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1238,6 +1238,9 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
 		if (!ret)
 			goto out;
 
+		/* Bail for signals. Probably ctrl-c from user */
+		if (signal_pending(current))
+			goto out;
 	}
 
 	/*
--
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