Received-SPF: pass (google.com: domain of linux-kernel+bounces-213487-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Thu, 13 Jun 2024 11:02:46 -0400
From: "Liam R. Howlett" <Liam.Howlett@oracle.com>
To: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org,
        linux-mm@kvack.org, akpm@linux-foundation.org, willy@infradead.org
Subject: Re: [PATCH v2 16/16] maple_tree: remove unneeded mas_wr_walk() in
 mas_store_prealloc()
Message-ID: <qa7zqgwm76eyjkkbqmvi73lvwuqbojjnx3zbppk2b4mdstji5m@fjicd6zbwfby>
Mail-Followup-To: "Liam R. Howlett" <Liam.Howlett@oracle.com>, 
	Sidhartha Kumar <sidhartha.kumar@oracle.com>, linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org, 
	linux-mm@kvack.org, akpm@linux-foundation.org, willy@infradead.org
References: <20240607185257.963768-1-sidhartha.kumar@oracle.com>
 <20240607185257.963768-17-sidhartha.kumar@oracle.com>
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20240607185257.963768-17-sidhartha.kumar@oracle.com>
User-Agent: NeoMutt/20231103
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: 
	=?us-ascii?Q?zQL81xiedyKsjgilCNQuqsjVstx7JedsAfdMwgiWmPwmHISspqlh2stxRhaX?=
 =?us-ascii?Q?i9A7Ex7MtZj5uo6Pn1RWizgQp1OBO5WpWp2mYmfvBY+GU2ZymiyxtbnmagMZ?=
 =?us-ascii?Q?mTJ+wLuhBydbbOHwIMf0A8Wg74j7KRxIKkkqrtt2gFv5s1sj3ZSmei+Q2VAS?=
 =?us-ascii?Q?/hZPHgADiEXaf9rM0nUNBhiycFGRJcq8krUR7W8U5t1xQK7K3YPqXvlKhjL4?=
 =?us-ascii?Q?UhYZpCqWhRswbJZFcNps15p6phgbXPBV9oK2r0ei33IFarX7BT9wmoA9K46R?=
 =?us-ascii?Q?WS0MSwsM+TRI1jxT/girURVcd9p2sjMAyOHP+1jt2wVaMnCo3kDO7POk4YkP?=
 =?us-ascii?Q?MFajWAoBYpbHriR1f/BoAQh8Ab0XlLtEbUYDZ8Hgrqn/+S/moMvNkpK4qtag?=
 =?us-ascii?Q?jFBHmizmDA5PJP+2cS64p7vMB1eqLxu/onz8c/i6Wv9hcO+DN54wn5TYHfK4?=
 =?us-ascii?Q?sxGquBoIWcXeMu4VTW4UbDkBRGLAUBctwpF2KwZZsNmW2nVyoc333sNNxhDz?=
 =?us-ascii?Q?DqBh8bwY1FZuq3FfqpVMjiudtuO9jCzxGY9IeGsF5mpYxe4iEbmHVWlP3kyL?=
 =?us-ascii?Q?NUV87gul7QxGNzC5PEPQVa33NA/QGM3PzcegxX3JJ4XcNJ3YkoNZrTVBaepu?=
 =?us-ascii?Q?x0m8SUElNTP3b31h9IFDzqaOMKQud01T2FbGMIWZtr7olOjmItvTyDbdxeay?=
 =?us-ascii?Q?Xl75F69dSBAZKHXYAuKL1y0lhAY5ivAkpMBhCWyD/bT7vCR+2jaBn4gkYhLZ?=
 =?us-ascii?Q?sijPQWa+a+AdSOAgztGWTG215xaxu2YORmsMZ8XHsg4osqwM4owFQ0TTpdlY?=
 =?us-ascii?Q?OXuGQ2cbfAdOtazwjoVpHGRgdLWhjJBcJhLCcYBuvarnKrvkUCe5HU9UBDGT?=
 =?us-ascii?Q?zmT81x3YDmMsARkIRMzTJhmxlv5g0Cg/7txRR9+r26o4TAq69C0VSgkMsC+G?=
 =?us-ascii?Q?kWilS8avl+kpA3CiOXqcUjblR2AzzlX2hfxy82rDePhyHDL5QUF8KoNjxbfO?=
 =?us-ascii?Q?vlxDmD1tp7pmEQ5leaSGMdU/jGiLkh38SF0XXhXL+cpiSmHIbBPnKrsSqGli?=
 =?us-ascii?Q?fhwUQFMC7/OjzQ5taVqJ9RP8kJeDi7SV5nmZWfbgWY1C7oRNUaEvQvvUL9ZZ?=
 =?us-ascii?Q?a8du5N0DOA77V9NwwL1mUq9GWGZMj9Iez3bu+jmV3aa4PDZbeIW5CFj1njiF?=
 =?us-ascii?Q?8pZQeeWNbL9E2gL9g5HFMs5X1Sbw0TLAxpfKSf/Nkdx+utrY0DiQnBwWU1IB?=
 =?us-ascii?Q?CXrLJeJzTVj+IxHFLYVcxBddFaZrmV5gcqgxxKaDqB4l8j5VMudq4V4lxOoC?=
 =?us-ascii?Q?eLWE5esMP1mwqK8PmfUvIdhM9eztGoswroeXhWfzUPS8Cx0jwYkkp8VB0l3e?=
 =?us-ascii?Q?aipQg82kJGBPz2vNKhiokPT8PvWUuRD60Hb5z6XZGGWAfJPDITLHISx6sGZ8?=
 =?us-ascii?Q?zVqf5FAWOwtCySqEO6w4Qy+m+tXJvll9ria36Vrsf0qfmg7lYUigjMgn6go/?=
 =?us-ascii?Q?lEZUsDO67PNiK4GVwooNm2n4n2HSYo2JXT/F2JWuo9d8QsebwiYaYvGgT/Im?=
 =?us-ascii?Q?D3SEhmWZcGpaurDRfrufkMJd7que1ddo9kFdc6XV1ziXKotXTxT1lQoNLg6h?=
 =?us-ascii?Q?kw=3D=3D?=
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 
	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
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: a739580e-48fa-49c6-1394-08dc8bb9e3a6
X-MS-Exchange-CrossTenant-AuthSource: DS0PR10MB7933.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jun 2024 15:02:48.6123
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 4Tz/Ar9iiP3YSn1G85kUW73SctoJDlk+KPj44fa4gZC9k+xe0B7dlKTYXoQXdnPTCkBA6FfojpK02uIPzFbO6g==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR10MB4279
X-Proofpoint-Virus-Version: vendor=baseguard
 engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16
 definitions=2024-06-13_08,2024-06-13_02,2024-05-17_01
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0
 mlxlogscore=999 bulkscore=0 suspectscore=0 spamscore=0 mlxscore=0
 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1
 engine=8.12.0-2405010000 definitions=main-2406130110
X-Proofpoint-ORIG-GUID: fqVl7AKV3_GKMgrWd9DqLLYLzMdY2Dc9
X-Proofpoint-GUID: fqVl7AKV3_GKMgrWd9DqLLYLzMdY2Dc9

* Sidhartha Kumar <sidhartha.kumar@oracle.com> [240607 14:53]:
> Users of mas_store_prealloc() enter this function with nodes already
> preallocated. This means the store type must be already set. We can then
> remove the call to mas_wr_store_type() and initialize the write state to
> continue the partial walk that was done when determining the store type.
> 
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> ---
>  lib/maple_tree.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 3d334e7c19a5..5854f25a4ae5 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -4027,9 +4027,6 @@ static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas)
>  		wr_mas->end_piv = wr_mas->pivots[wr_mas->offset_end];
>  	else
>  		wr_mas->end_piv = wr_mas->mas->max;
> -
> -	if (!wr_mas->entry)
> -		mas_wr_extend_null(wr_mas);
>  }
>  
>  static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
> @@ -5598,12 +5595,23 @@ void mas_store_prealloc(struct ma_state *mas, void *entry)
>  {
>  	MA_WR_STATE(wr_mas, mas, entry);
>  
> -	mas_wr_prealloc_setup(&wr_mas);
> -	mas_wr_store_type(&wr_mas);
> +	if (mas->store_type == wr_store_root) {
> +		mas_wr_prealloc_setup(&wr_mas);
> +		goto store;
> +	}
> +
> +	mas_wr_walk_descend(&wr_mas);
> +	if (mas->store_type != wr_spanning_store) {
> +		/* set wr_mas->content to current slot */
> +		wr_mas.content = mas_slot_locked(mas, wr_mas.slots, mas->offset);
> +		mas_wr_end_piv(&wr_mas);
> +	}
> +store:
>  	trace_ma_write(__func__, mas, 0, entry);
>  	mas_wr_store_entry(&wr_mas);
>  	MAS_WR_BUG_ON(&wr_mas, mas_is_err(mas));
>  	mas_destroy(mas);
> +

nit, this new line should probably be before the "store" label?

>  }
>  EXPORT_SYMBOL_GPL(mas_store_prealloc);
>  
> -- 
> 2.45.2
>