From: Jan Kara <jack@suse.cz>
To: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Cc: linux-ext4@vger.kernel.org, Theodore Ts'o <tytso@mit.edu>,
Ritesh Harjani <riteshh@linux.ibm.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Jan Kara <jack@suse.cz>, Kemeng Shi <shikemeng@huaweicloud.com>,
Ritesh Harjani <ritesh.list@gmail.com>
Subject: Re: [PATCH v2 04/12] ext4: Convert mballoc cr (criteria) to enum
Date: Tue, 6 Jun 2023 15:13:55 +0200 [thread overview]
Message-ID: <20230606131355.5npiivxse3q5d3rq@quack3> (raw)
In-Reply-To: <5d82fd467bdf70ea45bdaef810af3b146013946c.1685449706.git.ojaswin@linux.ibm.com>
On Tue 30-05-23 18:03:42, Ojaswin Mujoo wrote:
> Convert criteria to be an enum so it easier to maintain and
> update the tracefiles to use enum names. This change also makes
> it easier to insert new criterias in the future.
>
> There is no functional change in this patch.
>
> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
...
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index c075da665ec1..f9a4eaa10c6a 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -127,6 +127,23 @@ enum SHIFT_DIRECTION {
> SHIFT_RIGHT,
> };
>
> +/*
> + * Number of criterias defined. For each criteria, mballoc has slightly
> + * different way of finding the required blocks nad usually, higher the
> + * criteria the slower the allocation. We start at lower criterias and keep
> + * falling back to higher ones if we are not able to find any blocks.
> + */
> +#define EXT4_MB_NUM_CRS 4
> +/*
> + * All possible allocation criterias for mballoc
> + */
> +enum criteria {
> + CR0,
> + CR1,
> + CR2,
> + CR3,
> +};
Usually we define EXT4_MB_NUM_CRS like:
enum criteria {
CR0,
CR1,
CR2,
CR3,
EXT4_MB_NUM_CRS
};
> @@ -2626,7 +2626,7 @@ static noinline_for_stack int
> ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
> {
> ext4_group_t prefetch_grp = 0, ngroups, group, i;
> - int cr = -1, new_cr;
> + enum criteria cr, new_cr;
> int err = 0, first_err = 0;
> unsigned int nr = 0, prefetch_ios = 0;
> struct ext4_sb_info *sbi;
This can cause uninitialized use of 'cr' variable in the 'out:' label.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2023-06-06 13:14 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-30 12:33 [PATCH v2 00/12] multiblock allocator improvements Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 01/12] Revert "ext4: remove ac->ac_found > sbi->s_mb_min_to_scan dead check in ext4_mb_check_limits" Ojaswin Mujoo
2023-05-30 16:28 ` Sedat Dilek
2023-05-31 8:57 ` Ojaswin Mujoo
2023-06-02 13:45 ` Thorsten Leemhuis
2023-06-02 16:45 ` Theodore Ts'o
2023-05-30 12:33 ` [PATCH v2 02/12] ext4: mballoc: Remove useless setting of ac_criteria Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 03/12] ext4: Remove unused extern variables declaration Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 04/12] ext4: Convert mballoc cr (criteria) to enum Ojaswin Mujoo
2023-06-06 13:13 ` Jan Kara [this message]
2023-05-30 12:33 ` [PATCH v2 05/12] ext4: Add per CR extent scanned counter Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 06/12] ext4: Add counter to track successful allocation of goal length Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 07/12] ext4: Avoid scanning smaller extents in BG during CR1 Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 08/12] ext4: Don't skip prefetching BLOCK_UNINIT groups Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 09/12] ext4: Ensure ext4_mb_prefetch_fini() is called for all prefetched BGs Ojaswin Mujoo
2023-06-06 14:00 ` Guoqing Jiang
2023-06-27 6:51 ` Ojaswin Mujoo
2023-06-28 1:33 ` Guoqing Jiang
2023-05-30 12:33 ` [PATCH v2 10/12] ext4: Abstract out logic to search average fragment list Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 11/12] ext4: Add allocation criteria 1.5 (CR1_5) Ojaswin Mujoo
2023-06-07 10:21 ` Jan Kara
2023-06-08 14:45 ` Theodore Ts'o
2023-06-09 10:57 ` Ojaswin Mujoo
2023-05-30 12:33 ` [PATCH v2 12/12] ext4: Give symbolic names to mballoc criterias Ojaswin Mujoo
2023-06-07 10:39 ` Jan Kara
2023-06-09 3:14 ` [PATCH v2 00/12] multiblock allocator improvements Theodore Ts'o
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