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From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>, Nitin Gupta <ngupta@vflare.org>,
	Jerome Marchand <jmarchan@redhat.com>,
	Ganesh Mahendran <opensource.ganesh@gmail.com>
Subject: Re: [PATCH v1 2/2] zram: remove init_lock in zram_make_request
Date: Mon, 2 Feb 2015 14:09:12 +0900	[thread overview]
Message-ID: <20150202050912.GA443@swordfish> (raw)
In-Reply-To: <20150202042847.GG6402@blaptop>


the patch mosly looks good, except for one place:

On (02/02/15 13:28), Minchan Kim wrote:
> @@ -783,6 +812,8 @@ static ssize_t disksize_store(struct device *dev,
>  		goto out_destroy_comp;
>  	}
>  
> +	init_waitqueue_head(&zram->io_done);
> +	zram_meta_get(zram);

it was
+       init_completion(&zram->io_done);
+       atomic_set(&zram->refcount, 1);

I think we need to replace zram_meta_get(zram) with atomic_set(&zram->refcount, 1).

->refcount is 0 by default and atomic_inc_not_zero(&zram->refcount) will not
increment it here, nor anywhere else.


>  	zram->meta = meta;
>  	zram->comp = comp;
>  	zram->disksize = disksize;
> @@ -838,8 +869,8 @@ static ssize_t reset_store(struct device *dev,
>  	/* Make sure all pending I/O is finished */
>  	fsync_bdev(bdev);
>  	bdput(bdev);
> -

[..]

> @@ -1041,6 +1075,7 @@ static int create_device(struct zram *zram, int device_id)
>  	int ret = -ENOMEM;
>  
>  	init_rwsem(&zram->init_lock);
> +	atomic_set(&zram->refcount, 0);

sorry, I forgot that zram is kzalloc()-ated. so we can drop

	atomic_set(&zram->refcount, 0)

>  	zram->queue = blk_alloc_queue(GFP_KERNEL);
>  	if (!zram->queue) {


	-ss

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WARNING: multiple messages have this Message-ID (diff)
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>, Nitin Gupta <ngupta@vflare.org>,
	Jerome Marchand <jmarchan@redhat.com>,
	Ganesh Mahendran <opensource.ganesh@gmail.com>
Subject: Re: [PATCH v1 2/2] zram: remove init_lock in zram_make_request
Date: Mon, 2 Feb 2015 14:09:12 +0900	[thread overview]
Message-ID: <20150202050912.GA443@swordfish> (raw)
In-Reply-To: <20150202042847.GG6402@blaptop>


the patch mosly looks good, except for one place:

On (02/02/15 13:28), Minchan Kim wrote:
> @@ -783,6 +812,8 @@ static ssize_t disksize_store(struct device *dev,
>  		goto out_destroy_comp;
>  	}
>  
> +	init_waitqueue_head(&zram->io_done);
> +	zram_meta_get(zram);

it was
+       init_completion(&zram->io_done);
+       atomic_set(&zram->refcount, 1);

I think we need to replace zram_meta_get(zram) with atomic_set(&zram->refcount, 1).

->refcount is 0 by default and atomic_inc_not_zero(&zram->refcount) will not
increment it here, nor anywhere else.


>  	zram->meta = meta;
>  	zram->comp = comp;
>  	zram->disksize = disksize;
> @@ -838,8 +869,8 @@ static ssize_t reset_store(struct device *dev,
>  	/* Make sure all pending I/O is finished */
>  	fsync_bdev(bdev);
>  	bdput(bdev);
> -

[..]

> @@ -1041,6 +1075,7 @@ static int create_device(struct zram *zram, int device_id)
>  	int ret = -ENOMEM;
>  
>  	init_rwsem(&zram->init_lock);
> +	atomic_set(&zram->refcount, 0);

sorry, I forgot that zram is kzalloc()-ated. so we can drop

	atomic_set(&zram->refcount, 0)

>  	zram->queue = blk_alloc_queue(GFP_KERNEL);
>  	if (!zram->queue) {


	-ss

  reply	other threads:[~2015-02-02  5:09 UTC|newest]

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-28  8:15 [PATCH 1/2] zram: free meta table in zram_meta_free Minchan Kim
2015-01-28  8:15 ` [PATCH v1 2/2] zram: remove init_lock in zram_make_request Minchan Kim
2015-01-28 14:56   ` Sergey Senozhatsky
2015-01-28 14:56     ` Sergey Senozhatsky
2015-01-28 15:04     ` Sergey Senozhatsky
2015-01-28 15:04       ` Sergey Senozhatsky
2015-01-28 23:33     ` Minchan Kim
2015-01-28 23:33       ` Minchan Kim
2015-01-29  1:57       ` Sergey Senozhatsky
2015-01-29  2:01         ` Minchan Kim
2015-01-29  2:01           ` Minchan Kim
2015-01-29  2:22           ` Sergey Senozhatsky
2015-01-29  2:22             ` Sergey Senozhatsky
2015-01-29  5:28             ` Minchan Kim
2015-01-29  5:28               ` Minchan Kim
2015-01-29  6:06               ` Sergey Senozhatsky
2015-01-29  6:06                 ` Sergey Senozhatsky
2015-01-29  6:35                 ` Minchan Kim
2015-01-29  6:35                   ` Minchan Kim
2015-01-29  7:08                   ` Sergey Senozhatsky
2015-01-29  7:08                     ` Sergey Senozhatsky
2015-01-30 14:41                     ` Minchan Kim
2015-01-30 14:41                       ` Minchan Kim
2015-01-31 11:31                       ` Sergey Senozhatsky
2015-01-31 11:31                         ` Sergey Senozhatsky
2015-02-01 14:50                       ` Sergey Senozhatsky
2015-02-01 14:50                         ` Sergey Senozhatsky
2015-02-01 15:04                         ` Sergey Senozhatsky
2015-02-01 15:04                           ` Sergey Senozhatsky
2015-02-02  1:43                           ` Minchan Kim
2015-02-02  1:43                             ` Minchan Kim
2015-02-02  1:59                             ` Sergey Senozhatsky
2015-02-02  1:59                               ` Sergey Senozhatsky
2015-02-02  2:45                               ` Minchan Kim
2015-02-02  2:45                                 ` Minchan Kim
2015-02-02  3:47                                 ` Sergey Senozhatsky
2015-02-02  3:47                                   ` Sergey Senozhatsky
2015-02-02  1:30                         ` Minchan Kim
2015-02-02  1:30                           ` Minchan Kim
2015-02-02  1:48                           ` Sergey Senozhatsky
2015-02-02  1:48                             ` Sergey Senozhatsky
2015-02-02  2:44                             ` Minchan Kim
2015-02-02  2:44                               ` Minchan Kim
2015-02-02  4:01                               ` Sergey Senozhatsky
2015-02-02  4:01                                 ` Sergey Senozhatsky
2015-02-02  4:28                                 ` Minchan Kim
2015-02-02  4:28                                   ` Minchan Kim
2015-02-02  5:09                                   ` Sergey Senozhatsky [this message]
2015-02-02  5:09                                     ` Sergey Senozhatsky
2015-02-02  5:18                                     ` Minchan Kim
2015-02-02  5:18                                       ` Minchan Kim
2015-02-02  5:28                                       ` Sergey Senozhatsky
2015-02-02  5:28                                         ` Sergey Senozhatsky
2015-02-02  5:10                                   ` Minchan Kim
2015-02-02  5:10                                     ` Minchan Kim
2015-01-30  0:20                   ` Sergey Senozhatsky
2015-01-29 13:48   ` Ganesh Mahendran
2015-01-29 13:48     ` Ganesh Mahendran
2015-01-29 15:12     ` Sergey Senozhatsky
2015-01-29 15:12       ` Sergey Senozhatsky
2015-01-30  7:52       ` Ganesh Mahendran
2015-01-30  7:52         ` Ganesh Mahendran
2015-01-30  8:08         ` Sergey Senozhatsky
2015-01-30  8:08           ` Sergey Senozhatsky
2015-01-31  8:50           ` Ganesh Mahendran
2015-01-31  8:50             ` Ganesh Mahendran
2015-01-31 11:07             ` Sergey Senozhatsky
2015-01-31 11:07               ` Sergey Senozhatsky
2015-01-31 12:59               ` Ganesh Mahendran
2015-01-31 12:59                 ` Ganesh Mahendran
2015-01-28 14:19 ` [PATCH 1/2] zram: free meta table in zram_meta_free Sergey Senozhatsky
2015-01-28 14:19   ` Sergey Senozhatsky
2015-01-28 23:17   ` Minchan Kim
2015-01-28 23:17     ` Minchan Kim
2015-01-29  1:49     ` Ganesh Mahendran
2015-01-29  1:49       ` Ganesh Mahendran
  -- strict thread matches above, loose matches on Subject: below --
2015-02-02  3:41 [PATCH v1 2/2] zram: remove init_lock in zram_make_request Minchan Kim
2015-02-02  3:41 ` Minchan Kim
2015-02-02  5:59 ` Sergey Senozhatsky
2015-02-02  5:59   ` Sergey Senozhatsky
2015-02-02  6:18   ` Minchan Kim
2015-02-02  6:18     ` Minchan Kim
2015-02-02  7:06     ` Sergey Senozhatsky
2015-02-02  7:06       ` Sergey Senozhatsky
2015-02-03  1:54       ` Sergey Senozhatsky
2015-02-03  1:54         ` Sergey Senozhatsky
2015-02-03  3:02         ` Minchan Kim
2015-02-03  3:02           ` Minchan Kim
2015-02-03  3:56           ` Sergey Senozhatsky
2015-02-03  3:56             ` Sergey Senozhatsky

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