[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAGWkznEpn0NNTiYL-VYohcmboQ-kTDssiGZyi84BXf5i8+KA-Q@mail.gmail.com>
Date: Tue, 16 Jul 2024 14:14:24 +0800
From: Zhaoyang Huang <huangzhaoyang@...il.com>
To: Gao Xiang <hsiangkao@...ux.alibaba.com>
Cc: "zhaoyang.huang" <zhaoyang.huang@...soc.com>, Gao Xiang <xiang@...nel.org>,
Chao Yu <chao@...nel.org>, Yue Hu <huyue2@...lpad.com>,
Jeffle Xu <jefflexu@...ux.alibaba.com>, Sandeep Dhavale <dhavale@...gle.com>,
linux-erofs@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
steve.kang@...soc.com
Subject: Re: [PATCH] fs: fix schedule while atomic caused by gfp of erofs_allocpage
On Tue, Jul 16, 2024 at 1:50 PM Gao Xiang <hsiangkao@...ux.alibaba.com> wrote:
>
>
>
> On 2024/7/16 13:44, zhaoyang.huang wrote:
> > From: Zhaoyang Huang <zhaoyang.huang@...soc.com>
> >
> > scheduling while atomic was reported as below where the schedule_timeout
> > comes from too_many_isolated when doing direct_reclaim. Fix this by
> > masking GFP_DIRECT_RECLAIM from gfp.
> >
> > [ 175.610416][ T618] BUG: scheduling while atomic: kworker/u16:6/618/0x00000000
> > [ 175.643480][ T618] CPU: 2 PID: 618 Comm: kworker/u16:6 Tainted: G
> > [ 175.645791][ T618] Workqueue: loop20 loop_workfn
> > [ 175.646394][ T618] Call trace:
> > [ 175.646785][ T618] dump_backtrace+0xf4/0x140
> > [ 175.647345][ T618] show_stack+0x20/0x2c
> > [ 175.647846][ T618] dump_stack_lvl+0x60/0x84
> > [ 175.648394][ T618] dump_stack+0x18/0x24
> > [ 175.648895][ T618] __schedule_bug+0x64/0x90
> > [ 175.649445][ T618] __schedule+0x680/0x9b8
> > [ 175.649970][ T618] schedule+0x130/0x1b0
> > [ 175.650470][ T618] schedule_timeout+0xac/0x1d0
> > [ 175.651050][ T618] schedule_timeout_uninterruptible+0x24/0x34
> > [ 175.651789][ T618] __alloc_pages_slowpath+0x8dc/0x121c
> > [ 175.652455][ T618] __alloc_pages+0x294/0x2fc
> > [ 175.653011][ T618] erofs_allocpage+0x48/0x58
> > [ 175.653572][ T618] z_erofs_runqueue+0x314/0x8a4
> > [ 175.654161][ T618] z_erofs_readahead+0x258/0x318
> > [ 175.654761][ T618] read_pages+0x88/0x394
> > [ 175.655275][ T618] page_cache_ra_unbounded+0x1cc/0x23c
> > [ 175.655939][ T618] page_cache_ra_order+0x27c/0x33c
> > [ 175.656559][ T618] ondemand_readahead+0x224/0x334
> > [ 175.657169][ T618] page_cache_async_ra+0x60/0x9c
> > [ 175.657767][ T618] filemap_get_pages+0x19c/0x7cc
> > [ 175.658367][ T618] filemap_read+0xf0/0x484
> > [ 175.658901][ T618] generic_file_read_iter+0x4c/0x15c
> > [ 175.659543][ T618] do_iter_read+0x224/0x348
> > [ 175.660100][ T618] vfs_iter_read+0x24/0x38
> > [ 175.660635][ T618] loop_process_work+0x408/0xa68
> > [ 175.661236][ T618] loop_workfn+0x28/0x34
> > [ 175.661751][ T618] process_scheduled_works+0x254/0x4e8
> > [ 175.662417][ T618] worker_thread+0x24c/0x33c
> > [ 175.662974][ T618] kthread+0x110/0x1b8
> > [ 175.663465][ T618] ret_from_fork+0x10/0x20
> >
> > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@...soc.com>
>
> I don't see why it's an atomic context,
> so this patch is incorrect.
Sorry, I should provide more details. page_cache_ra_unbounded() will
call filemap_invalidate_lock_shared(mapping) to ensure the integrity
of page cache during readahead, which will disable preempt.
>
> Thanks,
> Gao Xiang
Powered by blists - more mailing lists