From: Jens Axboe <[email protected]>
To: Xiaoguang Wang <[email protected]>,
[email protected]
Cc: [email protected]
Subject: Re: [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set()
Date: Fri, 27 May 2022 11:09:44 -0600 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 5/27/22 10:53 AM, Xiaoguang Wang wrote:
> @@ -9650,12 +9646,15 @@ static void io_free_file_tables(struct io_file_table *table)
> table->bitmap = NULL;
> }
>
> -static inline void io_file_bitmap_set(struct io_file_table *table, int bit)
> +static inline void io_file_bitmap_set(struct io_ring_ctx *ctx, int bit)
> {
> + struct io_file_table *table = &ctx->file_table;
> +
> WARN_ON_ONCE(test_bit(bit, table->bitmap));
> __set_bit(bit, table->bitmap);
> - if (bit == table->alloc_hint)
> - table->alloc_hint++;
> + table->alloc_hint = bit + 1;
> + if (table->alloc_hint >= ctx->nr_user_files)
> + table->alloc_hint = 0;
> }
This branch isn't needed, we'll reset it when failing to get one anyway.
Much better than adding a branch to the fast path.
--
Jens Axboe
next prev parent reply other threads:[~2022-05-27 17:09 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-27 16:53 [PATCH 0/2] two bug fixes about direct fd install Xiaoguang Wang
2022-05-27 16:53 ` [PATCH 1/2] io_uring: fix file leaks around io_fixed_fd_install() Xiaoguang Wang
2022-05-27 16:53 ` [PATCH 2/2] io_uring: defer alloc_hint update to io_file_bitmap_set() Xiaoguang Wang
2022-05-27 17:09 ` Jens Axboe [this message]
2022-05-27 17:39 ` [PATCH v2] " Xiaoguang Wang
2022-05-27 18:03 ` Jens Axboe
2022-05-28 1:45 ` Xiaoguang Wang
2022-05-28 1:51 ` [PATCH v3] " Xiaoguang Wang
2022-05-28 2:14 ` Jens Axboe
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