From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED713ECE564 for ; Tue, 18 Sep 2018 15:29:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA731214DD for ; Tue, 18 Sep 2018 15:29:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AA731214DD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729975AbeIRVCh (ORCPT ); Tue, 18 Sep 2018 17:02:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:46292 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727756AbeIRVCh (ORCPT ); Tue, 18 Sep 2018 17:02:37 -0400 Received: from smtp.corp.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2FEF37F6CB; Tue, 18 Sep 2018 15:29:32 +0000 (UTC) Received: from tagon.redhat.com (ovpn-118-14.phx2.redhat.com [10.3.118.14]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC36088EB2; Tue, 18 Sep 2018 15:29:31 +0000 (UTC) From: Clark Williams To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: [PATCH RT] rt: convert mm/kasan/quarantine_lock to raw_spinlock Date: Tue, 18 Sep 2018 10:29:31 -0500 Message-Id: <20180918152931.17322-1-williams@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 18 Sep 2018 15:29:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The static lock quarantine_lock is used in mm/kasan/quarantine.c to protect the quarantine queue datastructures. It is taken inside quarantine queue manipulation routines (quarantine_put(), quarantine_reduce() and quarantine_remove_cache()), with IRQs disabled. This is no problem on a stock kernel but is problematic on an RT kernel where spin locks are converted to rt_mutex_t, which can sleep. Convert the quarantine_lock to a raw spinlock. The usage of quarantine_lock is confined to quarantine.c and the work performed while the lock is held is limited. Signed-off-by: Clark Williams --- mm/kasan/quarantine.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 3a8ddf8baf7d..b209dbaefde8 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -103,7 +103,7 @@ static int quarantine_head; static int quarantine_tail; /* Total size of all objects in global_quarantine across all batches. */ static unsigned long quarantine_size; -static DEFINE_SPINLOCK(quarantine_lock); +static DEFINE_RAW_SPINLOCK(quarantine_lock); DEFINE_STATIC_SRCU(remove_cache_srcu); /* Maximum size of the global queue. */ @@ -190,7 +190,7 @@ void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) { qlist_move_all(q, &temp); - spin_lock(&quarantine_lock); + raw_spin_lock(&quarantine_lock); WRITE_ONCE(quarantine_size, quarantine_size + temp.bytes); qlist_move_all(&temp, &global_quarantine[quarantine_tail]); if (global_quarantine[quarantine_tail].bytes >= @@ -203,7 +203,7 @@ void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache) if (new_tail != quarantine_head) quarantine_tail = new_tail; } - spin_unlock(&quarantine_lock); + raw_spin_unlock(&quarantine_lock); } local_irq_restore(flags); @@ -230,7 +230,7 @@ void quarantine_reduce(void) * expected case). */ srcu_idx = srcu_read_lock(&remove_cache_srcu); - spin_lock_irqsave(&quarantine_lock, flags); + raw_spin_lock_irqsave(&quarantine_lock, flags); /* * Update quarantine size in case of hotplug. Allocate a fraction of @@ -254,7 +254,7 @@ void quarantine_reduce(void) quarantine_head = 0; } - spin_unlock_irqrestore(&quarantine_lock, flags); + raw_spin_unlock_irqrestore(&quarantine_lock, flags); qlist_free_all(&to_free, NULL); srcu_read_unlock(&remove_cache_srcu, srcu_idx); @@ -310,17 +310,17 @@ void quarantine_remove_cache(struct kmem_cache *cache) */ on_each_cpu(per_cpu_remove_cache, cache, 1); - spin_lock_irqsave(&quarantine_lock, flags); + raw_spin_lock_irqsave(&quarantine_lock, flags); for (i = 0; i < QUARANTINE_BATCHES; i++) { if (qlist_empty(&global_quarantine[i])) continue; qlist_move_cache(&global_quarantine[i], &to_free, cache); /* Scanning whole quarantine can take a while. */ - spin_unlock_irqrestore(&quarantine_lock, flags); + raw_spin_unlock_irqrestore(&quarantine_lock, flags); cond_resched(); - spin_lock_irqsave(&quarantine_lock, flags); + raw_spin_lock_irqsave(&quarantine_lock, flags); } - spin_unlock_irqrestore(&quarantine_lock, flags); + raw_spin_unlock_irqrestore(&quarantine_lock, flags); qlist_free_all(&to_free, cache); -- 2.17.1