From: David Sterba <dsterba@suse.cz>
To: Qu Wenruo <wqu@suse.com>
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH] btrfs: refactor alloc_extent_buffer() to allocate-then-attach method
Date: Wed, 22 Nov 2023 15:38:15 +0100 [thread overview]
Message-ID: <20231122143815.GD11264@twin.jikos.cz> (raw)
In-Reply-To: <ffeb6b667a9ff0cf161f7dcd82899114782c0834.1700609426.git.wqu@suse.com>
On Wed, Nov 22, 2023 at 10:05:04AM +1030, Qu Wenruo wrote:
> - for (i = 0; i < num_pages; i++, index++) {
> - p = find_or_create_page(mapping, index, GFP_NOFS|__GFP_NOFAIL);
> - if (!p) {
> - exists = ERR_PTR(-ENOMEM);
> - btrfs_free_subpage(prealloc);
> - goto free_eb;
> + /* Alloc all pages. */
> + ret = btrfs_alloc_page_array(num_pages, eb->pages);
This looks promising. Assuming everything else works, this can be
changed to do:
- alloc_pages(order), the optimistic fast path, contig pages right from
the allocator, can fail
- fall back to btrfs_alloc_page_array(), this fills the array with
order-0 pages, similar what we have now, they could be contiguous
I wonder if we still can keep the __GFP_NOFAIL for the fallback
allocation, it's there right now and seems to work on sysmtems under
stress and does not cause random failures due to ENOMEM.
next prev parent reply other threads:[~2023-11-22 14:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 23:35 [PATCH] btrfs: refactor alloc_extent_buffer() to allocate-then-attach method Qu Wenruo
2023-11-22 14:14 ` Josef Bacik
2023-11-22 20:00 ` Qu Wenruo
2023-11-27 16:28 ` Josef Bacik
2023-11-27 22:17 ` Qu Wenruo
2023-11-22 14:38 ` David Sterba [this message]
2023-11-22 20:03 ` Qu Wenruo
2023-11-27 5:10 ` Should we still go __GFP_NOFAIL? (Was Re: [PATCH] btrfs: refactor alloc_extent_buffer() to allocate-then-attach method) Qu Wenruo
2023-11-27 16:19 ` Josef Bacik
2023-11-28 16:26 ` David Sterba
2023-11-28 20:06 ` Qu Wenruo
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