Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx3-phx2.redhat.com ([209.132.183.24]:37383 "EHLO mx3-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753119AbaHEPTm (ORCPT ); Tue, 5 Aug 2014 11:19:42 -0400 Received: from zmail10.collab.prod.int.phx2.redhat.com (zmail10.collab.prod.int.phx2.redhat.com [10.5.83.12]) by mx3-phx2.redhat.com (8.13.8/8.13.8) with ESMTP id s75FJgPx016830 for ; Tue, 5 Aug 2014 11:19:42 -0400 Date: Tue, 5 Aug 2014 11:19:42 -0400 (EDT) From: David Jeffery To: linux-nfs@vger.kernel.org Message-ID: <1630665170.14504134.1407251982055.JavaMail.zimbra@redhat.com> In-Reply-To: <1195286747.14503775.1407251856163.JavaMail.zimbra@redhat.com> Subject: [PATCH] nfs: Don't busy-wait on SIGKILL in __nfs_iocounter_wait MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: If a SIGKILL is sent to a task waiting in __nfs_iocounter_wait, it will busy-wait or soft lockup in its while loop. nfs_wait_bit_killable won't sleep, and the loop won't exit on the error return. Stop the busy-wait by breaking out of the loop when nfs_wait_bit_killable returns an error. Signed-off-by: David Jeffery --- I'm not completely confident this is the right solution. I would like feedback if the intention was to break out of this loop on error, or if we do need to wait here until io_count hits zero and use something other than nfs_wait_bit_killable to wait in case of SIGKILL. pagelist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 17fab89..f29a690 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -116,7 +116,7 @@ __nfs_iocounter_wait(struct nfs_io_counter *c) if (atomic_read(&c->io_count) == 0) break; ret = nfs_wait_bit_killable(&c->flags); - } while (atomic_read(&c->io_count) != 0); + } while (atomic_read(&c->io_count) != 0 && !ret); finish_wait(wq, &q.wait); return ret; }