Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932256Ab2FTWDV (ORCPT ); Wed, 20 Jun 2012 18:03:21 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:61584 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754850Ab2FTWDT (ORCPT ); Wed, 20 Jun 2012 18:03:19 -0400 From: mandeep.baines@gmail.com To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , linux-kernel@vger.kernel.org Cc: Mandeep Singh Baines , x86@kernel.org, Tejun Heo , Andrew Morton , Stephen Rothwell , Christoph Lameter , Olof Johansson Subject: [PATCH] x86, mm: only wait for flushes from online cpus Date: Wed, 20 Jun 2012 15:03:04 -0700 Message-Id: <1340229784-3686-1-git-send-email-msb@chromium.org> X-Mailer: git-send-email 1.7.3.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3075 Lines: 76 From: Mandeep Singh Baines A cpu in the mm_cpumask could go offline before we send the invalidate IPI causing us to wait forever. Bug Trace: <4>[10222.234548] WARNING: at ../../arch/x86/kernel/apic/ipi.c:113 default_send_IPI_mask_logical+0x58/0x73() <5>[10222.234633] Pid: 23605, comm: lmt-udev Tainted: G C 3.2.7 #1 <5>[10222.234639] Call Trace: <5>[10222.234651] [<8102e666>] warn_slowpath_common+0x68/0x7d <5>[10222.234661] [<81016c36>] ? default_send_IPI_mask_logical+0x58/0x73 <5>[10222.234670] [<8102e68f>] warn_slowpath_null+0x14/0x18 <5>[10222.234678] [<81016c36>] default_send_IPI_mask_logical+0x58/0x73 <5>[10222.234687] [<8101eec2>] flush_tlb_others_ipi+0x86/0xba <5>[10222.234696] [<8101f0bb>] flush_tlb_mm+0x5e/0x62 <5>[10222.234703] [<8101e36c>] pud_populate+0x2c/0x31 <5>[10222.234711] [<8101e409>] pgd_alloc+0x98/0xc7 <5>[10222.234719] [<8102c881>] mm_init.isra.38+0xcc/0xf3 <5>[10222.234727] [<8102cbc2>] dup_mm+0x68/0x34e <5>[10222.234736] [<8139bbae>] ? _cond_resched+0xd/0x21 <5>[10222.234745] [<810a5b7c>] ? kmem_cache_alloc+0x26/0xe2 <5>[10222.234753] [<8102d421>] ? copy_process+0x556/0xda6 <5>[10222.234761] [<8102d641>] copy_process+0x776/0xda6 <5>[10222.234770] [<8102dd5e>] do_fork+0xcb/0x1d4 <5>[10222.234778] [<810a8c96>] ? do_sync_write+0xd3/0xd3 <5>[10222.234786] [<810a94ab>] ? vfs_read+0x95/0xa2 <5>[10222.234795] [<81008850>] sys_clone+0x20/0x25 <5>[10222.234804] [<8139d8c5>] ptregs_clone+0x15/0x30 <5>[10222.234812] [<8139d7f7>] ? sysenter_do_call+0x12/0x26 <4>[10222.234818] ---[ end trace 31e095600f50fd48 ]--- <3>[10234.880183] BUG: soft lockup - CPU#0 stuck for 11s! [lmt-udev:23605] Addresses http://crosbug.com/31737 Signed-off-by: Mandeep Singh Baines Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Cc: Tejun Heo Cc: Andrew Morton Cc: Stephen Rothwell Cc: Christoph Lameter Cc: Olof Johansson --- arch/x86/mm/tlb.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 5e57e11..010090d 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -194,8 +194,13 @@ static void flush_tlb_others_ipi(const struct cpumask *cpumask, apic->send_IPI_mask(to_cpumask(f->flush_cpumask), INVALIDATE_TLB_VECTOR_START + sender); - while (!cpumask_empty(to_cpumask(f->flush_cpumask))) + while (!cpumask_empty(to_cpumask(f->flush_cpumask))) { + /* Only wait for online cpus */ + cpumask_and(to_cpumask(f->flush_cpumask), + to_cpumask(f->flush_cpumask), + cpu_online_mask); cpu_relax(); + } } f->flush_mm = NULL; -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/