Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933244Ab0FBVWR (ORCPT ); Wed, 2 Jun 2010 17:22:17 -0400 Received: from relay1.sgi.com ([192.48.179.29]:39580 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932980Ab0FBVVf (ORCPT ); Wed, 2 Jun 2010 17:21:35 -0400 To: linux-kernel@vger.kernel.org Subject: [PATCH 8/11] x86, UV: remove BAU check for stay-busy Cc: mingo@elte.hu, hpa@zytor.com, gregkh@suse.de Message-Id: From: Cliff Wickman Date: Wed, 02 Jun 2010 16:22:02 -0500 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3025 Lines: 88 Remove a faulty assumption that a long running BAU request has encountered a hardware problem and will never finish. Numalink congestion can make a request appear to have encountered such a problem, but it is not safe to cancel the request. If such a cancel is done but a reply is later received we can miss a TLB shootdown. We depend upon the max_bau_concurrent 'throttle' to prevent the stay-busy case from happening. Diffed against 2.6.34 -tip Signed-off-by: Cliff Wickman --- arch/x86/include/asm/uv/uv_bau.h | 1 - arch/x86/kernel/tlb_uv.c | 23 ----------------------- 2 files changed, 24 deletions(-) Index: 100531.linux-tip/arch/x86/kernel/tlb_uv.c =================================================================== --- 100531.linux-tip.orig/arch/x86/kernel/tlb_uv.c +++ 100531.linux-tip/arch/x86/kernel/tlb_uv.c @@ -405,12 +405,10 @@ static int uv_wait_completion(struct bau unsigned long mmr; unsigned long mask; cycles_t ttime; - cycles_t timeout_time; struct ptc_stats *stat = bcp->statp; struct bau_control *hmaster; hmaster = bcp->uvhub_master; - timeout_time = get_cycles() + bcp->timeout_interval; /* spin on the status MMR, waiting for it to go idle */ while ((descriptor_status = (((unsigned long) @@ -450,26 +448,6 @@ static int uv_wait_completion(struct bau * descriptor_status is still BUSY */ cpu_relax(); - relaxes++; - if (relaxes >= 10000) { - relaxes = 0; - if (get_cycles() > timeout_time) { - quiesce_local_uvhub(hmaster); - - /* single-thread the register change */ - spin_lock(&hmaster->masks_lock); - mmr = uv_read_local_mmr(mmr_offset); - mask = 0UL; - mask |= (3UL < right_shift); - mask = ~mask; - mmr &= mask; - uv_write_local_mmr(mmr_offset, mmr); - spin_unlock(&hmaster->masks_lock); - end_uvhub_quiesce(hmaster); - stat->s_busy++; - return FLUSH_GIVEUP; - } - } } } bcp->conseccompletes++; @@ -1580,7 +1558,6 @@ static void uv_init_per_cpu(int nuvhubs) for_each_present_cpu(cpu) { bcp = &per_cpu(bau_control, cpu); memset(bcp, 0, sizeof(struct bau_control)); - spin_lock_init(&bcp->masks_lock); pnode = uv_cpu_hub_info(cpu)->pnode; uvhub = uv_cpu_hub_info(cpu)->numa_blade_id; uvhub_mask |= (1 << uvhub); Index: 100531.linux-tip/arch/x86/include/asm/uv/uv_bau.h =================================================================== --- 100531.linux-tip.orig/arch/x86/include/asm/uv/uv_bau.h +++ 100531.linux-tip/arch/x86/include/asm/uv/uv_bau.h @@ -402,7 +402,6 @@ struct bau_control { unsigned short uvhub_quiesce; short socket_acknowledge_count[DEST_Q_SIZE]; cycles_t send_message; - spinlock_t masks_lock; spinlock_t uvhub_lock; spinlock_t queue_lock; /* tunables */ -- 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/