From: David Sterba <dsterba@suse.cz>
To: Filipe Manana <fdmanana@kernel.org>
Cc: linux-btrfs@vger.kernel.org, dsterba@suse.com
Subject: Re: [PATCH 0/3] btrfs: fix a couple sleeps while holding a spinlock
Date: Fri, 15 Jul 2022 14:01:30 +0200 [thread overview]
Message-ID: <20220715120129.GA13489@twin.jikos.cz> (raw)
In-Reply-To: <20220713135955.GA1114299@falcondesktop>
On Wed, Jul 13, 2022 at 02:59:55PM +0100, Filipe Manana wrote:
> On Wed, Jul 06, 2022 at 10:09:44AM +0100, fdmanana@kernel.org wrote:
> > From: Filipe Manana <fdmanana@suse.com>
> >
> > After the recent conversions of a couple radix trees to XArrays, we now
> > can end up attempting to sleep while holding a spinlock. This happens
> > because if xa_insert() allocates memory (using GFP_NOFS) it may need to
> > sleep (more likely to happen when under memory pressure). In the old
> > code this did not happen because we had radix_tree_preload() called
> > before taking the spinlocks.
> >
> > Filipe Manana (3):
> > btrfs: fix sleep while under a spinlock when allocating delayed inode
> > btrfs: fix sleep while under a spinlock when inserting a fs root
> > btrfs: free qgroup metadata without holding the fs roots lock
>
> David, are you going to pick these up or revert the patches that did the
> radix tree to xarray conversion?
Switching sping lock to mutex seems quite heavy weight, and reverting
xarray conversion is intrusive, so it's choosing from two bad options,
also that we haven't identified the problems earlier. Doing such changes
in rc6 is quite unpleasant, I'll explore the options.
next prev parent reply other threads:[~2022-07-15 12:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-06 9:09 [PATCH 0/3] btrfs: fix a couple sleeps while holding a spinlock fdmanana
2022-07-06 9:09 ` [PATCH 1/3] btrfs: fix sleep while under a spinlock when allocating delayed inode fdmanana
2022-07-06 9:09 ` [PATCH 2/3] btrfs: fix sleep while under a spinlock when inserting a fs root fdmanana
2022-07-06 9:09 ` [PATCH 3/3] btrfs: free qgroup metadata without holding the fs roots lock fdmanana
2022-07-07 16:31 ` [PATCH 0/3] btrfs: fix a couple sleeps while holding a spinlock David Sterba
2022-07-08 0:24 ` Matthew Wilcox
2022-07-12 11:45 ` Nikolay Borisov
2022-07-13 13:59 ` Filipe Manana
2022-07-15 12:01 ` David Sterba [this message]
2022-07-15 12:47 ` Nikolay Borisov
2022-07-15 16:52 ` David Sterba
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