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From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Dongyun Liu <dongyun.liu3@gmail.com>
Cc: minchan@kernel.org, senozhatsky@chromium.org, axboe@kernel.dk,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
	lincheng.yang@transsion.com, jiajun.ling@transsion.com,
	ldys2014@foxmail.com, Dongyun Liu <dongyun.liu@transsion.com>
Subject: Re: [PATCH] zram: Using GFP_ATOMIC instead of GFP_KERNEL to allocate bitmap memory in backing_dev_store
Date: Sat, 2 Dec 2023 00:39:56 +0900	[thread overview]
Message-ID: <20231201153956.GB404241@google.com> (raw)
In-Reply-To: <20231130152047.200169-1-dongyun.liu@transsion.com>

On (23/11/30 23:20), Dongyun Liu wrote:
> INFO: task init:331 blocked for more than 120 seconds.  "echo 0 >
> /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:init   state:D stack:    0 pid:    1 ppid:     0 flags:0x04000000
> Call trace:
>   __switch_to+0x244/0x4e4
>   __schedule+0x5bc/0xc48
>   schedule+0x80/0x164
>   rwsem_down_read_slowpath+0x4fc/0xf9c
>   __down_read+0x140/0x188
>   down_read+0x14/0x24
>   try_wakeup_wbd_thread+0x78/0x1ec [zram]
>   __zram_bvec_write+0x720/0x878 [zram]
>   zram_bvec_rw+0xa8/0x234 [zram]
>   zram_submit_bio+0x16c/0x268 [zram]
>   submit_bio_noacct+0x128/0x3c8
>   submit_bio+0x1cc/0x3d0
>   __swap_writepage+0x5c4/0xd4c
>   swap_writepage+0x130/0x158
>   pageout+0x1f4/0x478
>   shrink_page_list+0x9b4/0x1eb8
>   shrink_inactive_list+0x2f4/0xaa8
>   shrink_lruvec+0x184/0x340
>   shrink_node_memcgs+0x84/0x3a0
>   shrink_node+0x2c4/0x6c4
>   shrink_zones+0x16c/0x29c
>   do_try_to_free_pages+0xe4/0x2b4
>   try_to_free_pages+0x388/0x7b4
>   __alloc_pages_direct_reclaim+0x88/0x278
>   __alloc_pages_slowpath+0x4ec/0xf6c
>   __alloc_pages_nodemask+0x1f4/0x3dc
>   kmalloc_order+0x54/0x338
>   kmalloc_order_trace+0x34/0x1bc
>   __kmalloc+0x5e8/0x9c0
>   kvmalloc_node+0xa8/0x264
>   backing_dev_store+0x1a4/0x818 [zram]
>   dev_attr_store+0x38/0x8c
>   sysfs_kf_write+0x64/0xc4

Hmm, I'm not really following this backtrace. Backing device
configuration is only possible on un-initialized zram device.
If it's uninitialized, then why is it being used for swapout
later in the call stack?

  parent reply	other threads:[~2023-12-01 15:40 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-30 15:20 [PATCH] zram: Using GFP_ATOMIC instead of GFP_KERNEL to allocate bitmap memory in backing_dev_store Dongyun Liu
2023-11-30 15:37 ` Jens Axboe
2023-12-01  6:51   ` Dongyun Liu
2023-12-01 14:19     ` Jens Axboe
2023-12-01 15:28       ` Sergey Senozhatsky
2023-12-02 13:54       ` Dongyun Liu
2023-12-01 15:39 ` Sergey Senozhatsky [this message]
2023-12-02 15:50   ` Dongyun Liu
2023-12-03  1:23     ` Sergey Senozhatsky
2023-12-03 14:45       ` Dongyun Liu
2023-12-01 18:41 ` Minchan Kim

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