From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933371AbWFXJfF (ORCPT ); Sat, 24 Jun 2006 05:35:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933372AbWFXJfE (ORCPT ); Sat, 24 Jun 2006 05:35:04 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:64142 "EHLO einhorn.in-berlin.de") by vger.kernel.org with ESMTP id S933371AbWFXJfC (ORCPT ); Sat, 24 Jun 2006 05:35:02 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Sat, 24 Jun 2006 11:33:49 +0200 (CEST) From: Stefan Richter Subject: [RFC PATCH 2.6.17-mm1 2/3] ieee1394: coarser locking for tlabel allocation To: linux1394-devel@lists.sourceforge.net cc: linux-kernel@vger.kernel.org In-Reply-To: Message-ID: References: <449BEBFB.60302@s5r6.in-berlin.de> <200606230904.k5N94Al3005245@shell0.pdx.osdl.net> <30866.1151072338@warthog.cambridge.redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE X-Spam-Score: (0.891) AWL,BAYES_50 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Full parallelism in getting and freeing transaction labels of different nodes is not really required. Therefore reduce the number of locks for access to tlabel pools from 63 locks per host to 1 global lock. Signed-off-by: Stefan Richter --- drivers/ieee1394/ieee1394_transactions.c | 10 ++++++---- drivers/ieee1394/ieee1394_types.h | 2 -- 2 files changed, 6 insertions(+), 6 deletions(-) Index: linux/drivers/ieee1394/ieee1394_types.h =================================================================== --- linux.orig/drivers/ieee1394/ieee1394_types.h 2006-06-24 09:53:24.000000000 +0200 +++ linux/drivers/ieee1394/ieee1394_types.h 2006-06-24 10:02:15.000000000 +0200 @@ -16,7 +16,6 @@ /* Transaction Label handling */ struct hpsb_tlabel_pool { DECLARE_BITMAP(pool, 64); - spinlock_t lock; #ifdef __BIG_ENDIAN_BITFIELD u32 allocations :26 __attribute__((packed)); u32 next :6 __attribute__((packed)); @@ -30,7 +29,6 @@ struct hpsb_tlabel_pool { #define HPSB_TPOOL_INIT(_tp) \ do { \ bitmap_zero((_tp)->pool, 64); \ - spin_lock_init(&(_tp)->lock); \ (_tp)->next = 0; \ (_tp)->allocations = 0; \ sema_init(&(_tp)->count, 63); \ Index: linux/drivers/ieee1394/ieee1394_transactions.c =================================================================== --- linux.orig/drivers/ieee1394/ieee1394_transactions.c 2006-06-24 09:24:00.000000000 +0200 +++ linux/drivers/ieee1394/ieee1394_transactions.c 2006-06-24 10:08:35.000000000 +0200 @@ -31,6 +31,8 @@ packet->header[1] = (packet->host->node_id << 16) | (addr >> 32); \ packet->header[2] = addr & 0xffffffff +static spinlock_t hpsb_tlabel_lock = SPIN_LOCK_UNLOCKED; + static void fill_async_readquad(struct hpsb_packet *packet, u64 addr) { PREP_ASYNC_HEAD_ADDRESS(TCODE_READQ); @@ -149,7 +151,7 @@ int hpsb_get_tlabel(struct hpsb_packet * down(&tp->count); } - spin_lock_irqsave(&tp->lock, flags); + spin_lock_irqsave(&hpsb_tlabel_lock, flags); tlabel = find_next_zero_bit(tp->pool, 64, tp->next); if (tlabel > 63) @@ -160,7 +162,7 @@ int hpsb_get_tlabel(struct hpsb_packet * BUG_ON(test_and_set_bit(tlabel, tp->pool)); tp->allocations++; - spin_unlock_irqrestore(&tp->lock, flags); + spin_unlock_irqrestore(&hpsb_tlabel_lock, flags); packet->tlabel = tlabel; return 0; } @@ -188,9 +190,9 @@ void hpsb_free_tlabel(struct hpsb_packet BUG_ON(tlabel > 63 || tlabel < 0); - spin_lock_irqsave(&tp->lock, flags); + spin_lock_irqsave(&hpsb_tlabel_lock, flags); BUG_ON(!test_and_clear_bit(tlabel, tp->pool)); - spin_unlock_irqrestore(&tp->lock, flags); + spin_unlock_irqrestore(&hpsb_tlabel_lock, flags); up(&tp->count); }