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Date:   Wed, 23 Mar 2022 07:13:39 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Qu Wenruo <quwenruo.btrfs@gmx.com>
Cc:     Christoph Hellwig <hch@lst.de>, Josef Bacik <josef@toxicpanda.com>,
        David Sterba <dsterba@suse.com>, Qu Wenruo <wqu@suse.com>,
        Naohiro Aota <naohiro.aota@wdc.com>,
        linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 28/40] btrfs: do not allocate a btrfs_io_context in
 btrfs_map_bio
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References: <20220322155606.1267165-1-hch@lst.de> <20220322155606.1267165-29-hch@lst.de> <d9062a7d-c83c-06d7-50ac-272ffc0788f1@gmx.com>
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On Wed, Mar 23, 2022 at 09:14:06AM +0800, Qu Wenruo wrote:
> Really not a fan of enlarging btrfs_bio again and again.
>
> Especially for the btrfs_bio_stripe and btrfs_bio_stripe * part.
>
> Considering how many bytes we waste for SINGLE profile, now we need an
> extra pointer which we will never really use.

How do we waste memory?  We stop allocating the btrfs_io_context now
which can be quite big.