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=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 C1CBBC0650F for ; Mon, 5 Aug 2019 16:36:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8643F217D9 for ; Mon, 5 Aug 2019 16:36:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="R9HAs/WW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728854AbfHEQg1 (ORCPT ); Mon, 5 Aug 2019 12:36:27 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:51808 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726559AbfHEQg1 (ORCPT ); Mon, 5 Aug 2019 12:36:27 -0400 Received: by mail-wm1-f65.google.com with SMTP id 207so75405013wma.1; Mon, 05 Aug 2019 09:36:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=6IgxkcJMKz9Fy1Bo9Dhv0qnNKVUCye+F6rQM5HpFywU=; b=R9HAs/WWeJNgXR6IAv8PwPneDnspd43Kg+L40q6WUEkNAZce927JpS1Xhn17UVd/lf 3IVCffEadLNaPdWlvs+jab5/BJv50/OLioU0R2AO/vtTKVMs8NtxUhFufJUaSqhLc54/ fpl6+2OjFLZgPXPpX2s7eIXMB5ZEPy2E514rV9YpG2jk3RHsfPUdNb0f2P8LSG5Epqd8 zXHJYXbBm650wRYA4KOsoBPzmwCuVeYv6FvdgKgMKwkKCymOa7un09wBlYYoQ1fEQMg1 gC2ch/1UkJlgcBYmQOAvtfpU1egUaYQHm3xfCAsEDahdj7riOAe13mrt4L9OpuoXesbM 5pUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=6IgxkcJMKz9Fy1Bo9Dhv0qnNKVUCye+F6rQM5HpFywU=; b=rd95mgCV7vrKDfL7cHZqWDx3Ltcy2wQaxlnWDSf3r6r2wRfnwAYXHRB3rtxHnl5M4J 5T2lO4R0W/ojXsdgN7LY+l+vLMT/hhFO1HlDB5rmC73El2YolxyHv3V3gGxI3qi2r3Hj jnrxu2J9cam74J8UkwsLk3MRkh7DK5RFjDnPjQ4ASR9l7AbXQ/MlJcIkYBXCp0g8RoP2 InkBuXuEledVtljpSJI5+FguXLbh2WYJx5cmbOcjz5/URibUIdaZjMtRxMIefcV7iI8x nyLFpjA3HY3RBmOltJCW57ZzFhsz8BKmgZgbZjsuUec/1tSTq63lMrRrDDU0qhDAUC6b HuVw== X-Gm-Message-State: APjAAAUWGJrIA6VCDF0WbPVIeuOMOWap0SRwXgJxyh9MELADhFWVZx9A qfjEqbraOw5V/Bdz3YvR1ws= X-Google-Smtp-Source: APXvYqzbpu3kVYNUDDAXxV+dNYJGnZMcPvxxEVAAIi6y9bRvr28PjCrHtWzjJfI+1O7EG2m0xfkNRQ== X-Received: by 2002:a7b:c4d0:: with SMTP id g16mr19909838wmk.88.1565022983407; Mon, 05 Aug 2019 09:36:23 -0700 (PDT) Received: from archlinux-threadripper ([2a01:4f8:222:2f1b::2]) by smtp.gmail.com with ESMTPSA id v65sm99792928wme.31.2019.08.05.09.36.22 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Mon, 05 Aug 2019 09:36:22 -0700 (PDT) Date: Mon, 5 Aug 2019 09:36:21 -0700 From: Nathan Chancellor To: Nikolay Borisov Cc: linux-btrfs@vger.kernel.org, paulmck@linux.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] btrfs: Hook btrfs' DRW lock to locktorture infrastructure Message-ID: <20190805163621.GA94502@archlinux-threadripper> References: <20190719083949.5351-1-nborisov@suse.com> <20190719084808.5877-1-nborisov@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190719084808.5877-1-nborisov@suse.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 19, 2019 at 11:48:08AM +0300, Nikolay Borisov wrote: > Signed-off-by: Nikolay Borisov > --- > > Hello Paul, > > Here is the code I used to test the DRW lock via the lock torture infrastructure. > It's rather ugly but got the job done for me. It's definitely not in a mergeable > form. At the very least I think including btrfs headers constitutes a violation > of separation of different subsystems. Would it be acceptable to guard them > behind something like "#if BTRFS && BTRFS_DEBUG" ? > > I'm really posting this just for posterity/provenance purposes. I'm fine with > dropping the patch. > > > fs/btrfs/locking.h | 1 + > kernel/locking/locktorture.c | 77 +++++++++++++++++++++++++++++++++++- > 2 files changed, 77 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h > index 44378c65f843..27627d4fd3a9 100644 > --- a/fs/btrfs/locking.h > +++ b/fs/btrfs/locking.h > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include "extent_io.h" > > #define BTRFS_WRITE_LOCK 1 > #define BTRFS_READ_LOCK 2 > diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c > index 80a463d31a8d..774e10a25876 100644 > --- a/kernel/locking/locktorture.c > +++ b/kernel/locking/locktorture.c > @@ -30,6 +30,8 @@ > #include > #include > #include > +#include "../../fs/btrfs/ctree.h" > +#include "../../fs/btrfs/locking.h" > > MODULE_LICENSE("GPL"); > MODULE_AUTHOR("Paul E. McKenney "); > @@ -85,6 +87,7 @@ struct lock_torture_ops { > > unsigned long flags; /* for irq spinlocks */ > const char *name; > + bool multiple; > }; > > struct lock_torture_cxt { > @@ -600,6 +603,7 @@ static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem) > percpu_up_read(&pcpu_rwsem); > } > > + > static struct lock_torture_ops percpu_rwsem_lock_ops = { > .init = torture_percpu_rwsem_init, > .writelock = torture_percpu_rwsem_down_write, > @@ -612,6 +616,76 @@ static struct lock_torture_ops percpu_rwsem_lock_ops = { > .name = "percpu_rwsem_lock" > }; > > +static struct btrfs_drw_lock torture_drw_lock; > + > +void torture_drw_init(void) > +{ > + BUG_ON(btrfs_drw_lock_init(&torture_drw_lock)); > +} > + > +static int torture_drw_write_lock(void) __acquires(torture_drw_lock) > +{ > + btrfs_drw_write_lock(&torture_drw_lock); > + return 0; > +} > + > +static void torture_drw_write_unlock(void) __releases(torture_drw_lock) > +{ > + btrfs_drw_write_unlock(&torture_drw_lock); > +} > + > +static int torture_drw_read_lock(void) __acquires(torture_drw_lock) > +{ > + btrfs_drw_read_lock(&torture_drw_lock); > + return 0; > +} > + > +static void torture_drw_read_unlock(void) __releases(torture_drw_lock) > +{ > + btrfs_drw_read_unlock(&torture_drw_lock); > +} > + > +static void torture_drw_write_delay(struct torture_random_state *trsp) > +{ > + const unsigned long longdelay_ms = 100; > + > + /* We want a long delay occasionally to force massive contention. */ > + if (!(torture_random(trsp) % > + (cxt.nrealwriters_stress * 2000 * longdelay_ms))) > + mdelay(longdelay_ms * 10); > + else > + mdelay(longdelay_ms / 10); > + if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) > + torture_preempt_schedule(); /* Allow test to be preempted. */ > +} > + > +static void torture_drw_read_delay(struct torture_random_state *trsp) > +{ > + const unsigned long longdelay_ms = 100; > + > + /* We want a long delay occasionally to force massive contention. */ > + if (!(torture_random(trsp) % > + (cxt.nrealreaders_stress * 2000 * longdelay_ms))) > + mdelay(longdelay_ms * 2); > + else > + mdelay(longdelay_ms / 2); > + if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000))) > + torture_preempt_schedule(); /* Allow test to be preempted. */ > +} > + > +static struct lock_torture_ops btrfs_drw_lock_ops = { > + .init = torture_drw_init, > + .writelock = torture_drw_write_lock, > + .write_delay = torture_drw_write_delay, > + .task_boost = torture_boost_dummy, > + .writeunlock = torture_drw_write_unlock, > + .readlock = torture_drw_read_lock, > + .read_delay = torture_drw_read_delay, /* figure what to do with this */ > + .readunlock = torture_drw_read_unlock, > + .multiple = true, > + .name = "btrfs_drw_lock" > +}; > + > /* > * Lock torture writer kthread. Repeatedly acquires and releases > * the lock, checking for duplicate acquisitions. > @@ -630,7 +704,7 @@ static int lock_torture_writer(void *arg) > > cxt.cur_ops->task_boost(&rand); > cxt.cur_ops->writelock(); > - if (WARN_ON_ONCE(lock_is_write_held)) > + if (!cxt.cur_ops->multiple && WARN_ON_ONCE(lock_is_write_held)) > lwsp->n_lock_fail++; > lock_is_write_held = 1; > if (WARN_ON_ONCE(lock_is_read_held)) > @@ -852,6 +926,7 @@ static int __init lock_torture_init(void) > #endif > &rwsem_lock_ops, > &percpu_rwsem_lock_ops, > + &btrfs_drw_lock_ops > }; > > if (!torture_init_begin(torture_type, verbose)) > -- > 2.17.1 > Looks like this is in next-20190805 and causes a link time error when CONFIG_BTRFS_FS is unset: LD vmlinux.o MODPOST vmlinux.o MODINFO modules.builtin.modinfo ld.lld: error: undefined symbol: btrfs_drw_lock_init >>> referenced by locktorture.c >>> locking/locktorture.o:(torture_drw_init) in archive kernel/built-in.a ld.lld: error: undefined symbol: btrfs_drw_write_lock >>> referenced by locktorture.c >>> locking/locktorture.o:(torture_drw_write_lock) in archive kernel/built-in.a ld.lld: error: undefined symbol: btrfs_drw_write_unlock >>> referenced by locktorture.c >>> locking/locktorture.o:(torture_drw_write_unlock) in archive kernel/built-in.a ld.lld: error: undefined symbol: btrfs_drw_read_lock >>> referenced by locktorture.c >>> locking/locktorture.o:(torture_drw_read_lock) in archive kernel/built-in.a ld.lld: error: undefined symbol: btrfs_drw_read_unlock >>> referenced by locktorture.c >>> locking/locktorture.o:(torture_drw_read_unlock) in archive kernel/built-in.a If this commit is to remain around, there should probably be static inline stubs in fs/btrfs/locking.h. Apologies if this has already been reported, I still see the commit in the btrfs for-next branch. Cheers, Nathan