linux-ext4 - Re: [PATCH] jbd2: remove bunch of empty lines with jbd2 debug

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Date:   Fri, 18 May 2018 15:19:14 +0200
From:   Jan Kara <jack@...e.cz>
To:     Wang Shilong <wangshilong1991@...il.com>
Cc:     linux-ext4@...r.kernel.org, tytso@....edu, jack@...e.com,
        Wang Shilong <wshilong@....com>
Subject: Re: [PATCH] jbd2: remove bunch of empty lines with jbd2 debug

On Fri 18-05-18 22:08:07, Wang Shilong wrote:
> From: Wang Shilong <wshilong@....com>
> 
> See following dmesg output with jbd2 debug enabled:
> 
> ...(start_this_handle, 313): New handle 00000000c88d6ceb going live.
> 
> ...(start_this_handle, 383): Handle 00000000c88d6ceb given 53 credits (total 53, free 32681)
> 
> ...(do_get_write_access, 838): journal_head 0000000002856fc0, force_copy 0
> 
> ...(jbd2_journal_cancel_revoke, 421): journal_head 0000000002856fc0, cancelling revoke
> 
> We have an extra line with every messages, this is a waste of buffer,
> we can fix it by removing "\n" in the caller or remove it in
> the __jbd2_debug(), i checked every jbd2_debug() passed '\n' explicitly.
> 
> To avoid more lines, let's remove it inside __jbd2_debug().
> 
> Signed-off-by: Wang Shilong <wshilong@....com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@...e.cz>

								Honza

> ---
>  fs/jbd2/journal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index dfb0579..e942701 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -114,7 +114,7 @@ void __jbd2_debug(int level, const char *file, const char *func,
>  	va_start(args, fmt);
>  	vaf.fmt = fmt;
>  	vaf.va = &args;
> -	printk(KERN_DEBUG "%s: (%s, %u): %pV\n", file, func, line, &vaf);
> +	printk(KERN_DEBUG "%s: (%s, %u): %pV", file, func, line, &vaf);
>  	va_end(args);
>  }
>  EXPORT_SYMBOL(__jbd2_debug);
> -- 
> 1.8.3.1
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR