From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756615AbZCFP4i (ORCPT ); Fri, 6 Mar 2009 10:56:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756363AbZCFPzt (ORCPT ); Fri, 6 Mar 2009 10:55:49 -0500 Received: from hera.kernel.org ([140.211.167.34]:35726 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756337AbZCFPzs (ORCPT ); Fri, 6 Mar 2009 10:55:48 -0500 From: Tejun Heo To: mingo@elte.hu, rusty@rustcorp.com.au, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, npiggin@suse.de, akpm@linux-foundation.org Cc: Tejun Heo Subject: [PATCH 3/4] percpu: move fully free chunk reclamation into a work Date: Sat, 7 Mar 2009 00:54:42 +0900 Message-Id: <1236354883-25063-4-git-send-email-tj@kernel.org> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <1236354883-25063-1-git-send-email-tj@kernel.org> References: <1236354883-25063-1-git-send-email-tj@kernel.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 06 Mar 2009 15:54:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Impact: code reorganization for later changes Do fully free chunk reclamation using a work. This change is to prepare for locking changes. Signed-off-by: Tejun Heo --- mm/percpu.c | 48 ++++++++++++++++++++++++++++++++++++++---------- 1 files changed, 38 insertions(+), 10 deletions(-) diff --git a/mm/percpu.c b/mm/percpu.c index 7d9bc35..4c8a419 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -63,6 +63,7 @@ #include #include #include +#include #include #include @@ -118,6 +119,10 @@ static DEFINE_MUTEX(pcpu_mutex); static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ static struct rb_root pcpu_addr_root = RB_ROOT; /* chunks by address */ +/* reclaim work to release fully free chunks, scheduled from free path */ +static void pcpu_reclaim(struct work_struct *work); +static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); + static int __pcpu_size_to_slot(int size) { int highbit = fls(size); /* size is in bytes */ @@ -846,13 +851,37 @@ void *__alloc_reserved_percpu(size_t size, size_t align) return pcpu_alloc(size, align, true); } -static void pcpu_kill_chunk(struct pcpu_chunk *chunk) +/** + * pcpu_reclaim - reclaim fully free chunks, workqueue function + * @work: unused + * + * Reclaim all fully free chunks except for the first one. + */ +static void pcpu_reclaim(struct work_struct *work) { - WARN_ON(chunk->immutable); - pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false); - list_del(&chunk->list); - rb_erase(&chunk->rb_node, &pcpu_addr_root); - free_pcpu_chunk(chunk); + LIST_HEAD(todo); + struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; + struct pcpu_chunk *chunk, *next; + + mutex_lock(&pcpu_mutex); + + list_for_each_entry_safe(chunk, next, head, list) { + WARN_ON(chunk->immutable); + + /* spare the first one */ + if (chunk == list_first_entry(head, struct pcpu_chunk, list)) + continue; + + rb_erase(&chunk->rb_node, &pcpu_addr_root); + list_move(&chunk->list, &todo); + } + + mutex_unlock(&pcpu_mutex); + + list_for_each_entry_safe(chunk, next, &todo, list) { + pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false); + free_pcpu_chunk(chunk); + } } /** @@ -877,14 +906,13 @@ void free_percpu(void *ptr) pcpu_free_area(chunk, off); - /* the chunk became fully free, kill one if there are other free ones */ + /* if there are more than one fully free chunks, wake up grim reaper */ if (chunk->free_size == pcpu_unit_size) { struct pcpu_chunk *pos; - list_for_each_entry(pos, - &pcpu_slot[pcpu_chunk_slot(chunk)], list) + list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) if (pos != chunk) { - pcpu_kill_chunk(pos); + schedule_work(&pcpu_reclaim_work); break; } } -- 1.6.0.2