linux-kernel - Re: [PATCH] remove unnecessary initial allocation of vc

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Message-ID: <20170221141138.z33noszsfzkauyrs@var.youpi.perso.aquilenet.fr>
Date:   Tue, 21 Feb 2017 15:11:38 +0100
From:   Samuel Thibault <samuel.thibault@...-lyon.org>
To:     "Pranay Kr. Srivastava" <pranjas@...il.com>
Cc:     w.d.hubbs@...il.com, chris@...-brannons.com, kirk@...sers.ca,
        gregkh@...uxfoundation.org, sfr@...b.auug.org.au,
        speakup@...ux-speakup.org, devel@...verdev.osuosl.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] remove unnecessary initial allocation of vc

Pranay Kr. Srivastava, on mar. 21 févr. 2017 19:33:32 +0530, wrote:
> This patch removes the unnecessary allocation of
> current foreground vc during initialization.
> 
> Also change the prototype of speakup_allocate to take
> extra argument of gfp_* flags. Thus not requiring
> GFP_ATOMIC during initialization.
> 
> Signed-off-by: Pranay Kr. Srivastava <pranjas@...il.com>

Reviewed-by: Samuel Thibault <samuel.thibault@...-lyon.org>

Just add in the log that it's unnecessary because the for loop below
does the initialization already.

> ---
>  drivers/staging/speakup/main.c | 19 ++++---------------
>  1 file changed, 4 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/staging/speakup/main.c b/drivers/staging/speakup/main.c
> index ad95905..4437b39 100644
> --- a/drivers/staging/speakup/main.c
> +++ b/drivers/staging/speakup/main.c
> @@ -1328,14 +1328,14 @@ static int edit_bits(struct vc_data *vc, u_char type, u_char ch, u_short key)
>  }
>  
>  /* Allocation concurrency is protected by the console semaphore */
> -static int speakup_allocate(struct vc_data *vc)
> +static int speakup_allocate(struct vc_data *vc, gfp_t gfp_flags)
>  {
>  	int vc_num;
>  
>  	vc_num = vc->vc_num;
>  	if (speakup_console[vc_num] == NULL) {
>  		speakup_console[vc_num] = kzalloc(sizeof(*speakup_console[0]),
> -						  GFP_ATOMIC);
> +						  gfp_flags);
>  		if (speakup_console[vc_num] == NULL)
>  			return -ENOMEM;
>  		speakup_date(vc);
> @@ -2258,7 +2258,7 @@ static int vt_notifier_call(struct notifier_block *nb,
>  	switch (code) {
>  	case VT_ALLOCATE:
>  		if (vc->vc_mode == KD_TEXT)
> -			speakup_allocate(vc);
> +			speakup_allocate(vc, GFP_ATOMIC);
>  		break;
>  	case VT_DEALLOCATE:
>  		speakup_deallocate(vc);
> @@ -2318,7 +2318,6 @@ static int __init speakup_init(void)
>  {
>  	int i;
>  	long err = 0;
> -	struct st_spk_t *first_console;
>  	struct vc_data *vc = vc_cons[fg_console].d;
>  	struct var_t *var;
>  
> @@ -2343,18 +2342,9 @@ static int __init speakup_init(void)
>  	if (err)
>  		goto error_virtkeyboard;
>  
> -	first_console = kzalloc(sizeof(*first_console), GFP_KERNEL);
> -	if (!first_console) {
> -		err = -ENOMEM;
> -		goto error_alloc;
> -	}
> -
> -	speakup_console[vc->vc_num] = first_console;
> -	speakup_date(vc);
> -
>  	for (i = 0; i < MAX_NR_CONSOLES; i++)
>  		if (vc_cons[i].d) {
> -			err = speakup_allocate(vc_cons[i].d);
> +			err = speakup_allocate(vc_cons[i].d, GFP_KERNEL);
>  			if (err)
>  				goto error_kobjects;
>  		}
> @@ -2413,7 +2403,6 @@ static int __init speakup_init(void)
>  	for (i = 0; i < MAX_NR_CONSOLES; i++)
>  		kfree(speakup_console[i]);
>  
> -error_alloc:
>  	speakup_remove_virtual_keyboard();
>  
>  error_virtkeyboard:
> -- 
> 2.10.2
> 

-- 
Samuel
 Battery 1: charging, 90%, charging at zero rate - will never fully charge.
 -+- acpi - et pourtant, ca monte -+-