From: Nikolay Borisov <nborisov@suse.com>
To: dsterba@suse.cz, linux-btrfs@vger.kernel.org
Subject: Re: [PATCH v4 08/15] btrfs: Stop using call_rcu for device freeing
Date: Mon, 1 Apr 2019 20:20:56 +0300 [thread overview]
Message-ID: <318e1daa-3bef-3474-cba4-ec6faa527e26@suse.com> (raw)
In-Reply-To: <20190401170722.GY29086@twin.jikos.cz>
On 1.04.19 г. 20:07 ч., David Sterba wrote:
> On Wed, Mar 27, 2019 at 02:24:11PM +0200, Nikolay Borisov wrote:
>> btrfs_device structs are freed from RCU context since device iteration
>> is protected by RCU. Currently this is achieved by using call_rcu since
>> no blocking functions are called within btrfs_free_device. Future
>> refactoring of pending/pinned chunks will require calling sleeping
>> functions. This patch is in preparation for these changes by simply
>> switching from RCU callbacks to explicit calls of synchronize_rcu and
>> calling btrfs_free_device directly.
>
> A paragraph why this transition is correct would be good. It looks
> correct to me, so this is a matter of documentation.
>
Well call_rcu and synchronize_rcu() are functionally equivalent in that
they run the code that follows them after a grace period has expired.
next prev parent reply other threads:[~2019-04-01 17:21 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-27 12:24 [PATCH v4 00/15] FITRIM improvement Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 01/15] btrfs: Honour FITRIM range constraints during free space trim Nikolay Borisov
2019-05-25 2:30 ` Qu Wenruo
2019-03-27 12:24 ` [PATCH v4 02/15] btrfs: combine device update operations during transaction commit Nikolay Borisov
2019-05-03 10:23 ` David Sterba
2019-03-27 12:24 ` [PATCH v4 03/15] btrfs: Handle pending/pinned chunks before blockgroup relocation during device shrink Nikolay Borisov
2019-04-01 18:26 ` David Sterba
2019-04-02 5:55 ` Nikolay Borisov
2019-04-02 15:52 ` David Sterba
2019-03-27 12:24 ` [PATCH v4 04/15] btrfs: Rename and export clear_btree_io_tree Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 05/15] btrfs: Populate ->orig_block_len during read_one_chunk Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 06/15] btrfs: Introduce new bits for device allocation tree Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 07/15] btrfs: Implement set_extent_bits_nowait Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 08/15] btrfs: Stop using call_rcu for device freeing Nikolay Borisov
2019-04-01 17:07 ` David Sterba
2019-04-01 17:20 ` Nikolay Borisov [this message]
2019-04-02 16:12 ` David Sterba
2019-03-27 12:24 ` [PATCH v4 09/15] btrfs: replace pending/pinned chunks lists with io tree Nikolay Borisov
2024-02-29 10:00 ` Alex Lyakas
2024-02-29 10:54 ` Filipe Manana
2024-02-29 11:07 ` Alex Lyakas
2019-03-27 12:24 ` [PATCH v4 10/15] btrfs: Transpose btrfs_close_devices/btrfs_mapping_tree_free in close_ctree Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 11/15] btrfs: Remove 'trans' argument from find_free_dev_extent(_start) Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 12/15] btrfs: Factor out in_range macro Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 13/15] btrfs: Optimize unallocated chunks discard Nikolay Borisov
2019-04-01 18:44 ` David Sterba
2019-04-02 8:01 ` Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 14/15] btrfs: Implement find_first_clear_extent_bit Nikolay Borisov
2019-03-27 12:24 ` [PATCH v4 15/15] btrfs: Switch btrfs_trim_free_extents to find_first_clear_extent_bit Nikolay Borisov
2019-03-28 23:18 ` [PATCH v4 00/15] FITRIM improvement David Sterba
2019-03-29 6:20 ` Nikolay Borisov
2019-03-29 6:55 ` Qu Wenruo
2019-04-03 13:46 ` David Sterba
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