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Groups > linux.kernel > #1591265
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail |
| Date | 2017-03-02 17:40 +0100 |
| Message-ID | <tgBVN-4ZX-23@gated-at.bofh.it> (permalink) |
| References | <tgAZH-4mT-1@gated-at.bofh.it> <tgB9n-4qi-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
I've just realized that Darrick was not on the CC list. Let's add him.
I believe this patch should go in in the current cycle because
5d17a73a2ebe was merged in this merge window and it can be abused...
The other patch [1] is not that urgent.
[1] http://lkml.kernel.org/r/20170302154541.16155-2-mhocko@kernel.org
On Thu 02-03-17 16:45:40, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> Even though kmem_zalloc_greedy is documented it might fail the current
> code doesn't really implement this properly and loops on the smallest
> allowed size for ever. This is a problem because vzalloc might fail
> permanently - we might run out of vmalloc space or since 5d17a73a2ebe
> ("vmalloc: back off when the current task is killed") when the current
> task is killed. The later one makes the failure scenario much more
> probable than it used to be because it makes vmalloc() failures
> permanent for tasks with fatal signals pending.. Fix this by bailing out
> if the minimum size request failed.
>
> This has been noticed by a hung generic/269 xfstest by Xiong Zhou.
>
> fsstress: vmalloc: allocation failure, allocated 12288 of 20480 bytes, mode:0x14080c2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO), nodemask=(null)
> fsstress cpuset=/ mems_allowed=0-1
> CPU: 1 PID: 23460 Comm: fsstress Not tainted 4.10.0-master-45554b2+ #21
> Hardware name: HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 10/05/2016
> Call Trace:
> dump_stack+0x63/0x87
> warn_alloc+0x114/0x1c0
> ? alloc_pages_current+0x88/0x120
> __vmalloc_node_range+0x250/0x2a0
> ? kmem_zalloc_greedy+0x2b/0x40 [xfs]
> ? free_hot_cold_page+0x21f/0x280
> vzalloc+0x54/0x60
> ? kmem_zalloc_greedy+0x2b/0x40 [xfs]
> kmem_zalloc_greedy+0x2b/0x40 [xfs]
> xfs_bulkstat+0x11b/0x730 [xfs]
> ? xfs_bulkstat_one_int+0x340/0x340 [xfs]
> ? selinux_capable+0x20/0x30
> ? security_capable+0x48/0x60
> xfs_ioc_bulkstat+0xe4/0x190 [xfs]
> xfs_file_ioctl+0x9dd/0xad0 [xfs]
> ? do_filp_open+0xa5/0x100
> do_vfs_ioctl+0xa7/0x5e0
> SyS_ioctl+0x79/0x90
> do_syscall_64+0x67/0x180
> entry_SYSCALL64_slow_path+0x25/0x25
>
> fsstress keeps looping inside kmem_zalloc_greedy without any way out
> because vmalloc keeps failing due to fatal_signal_pending.
>
> Reported-by: Xiong Zhou <xzhou@redhat.com>
> Analyzed-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> ---
> fs/xfs/kmem.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
> index 339c696bbc01..ee95f5c6db45 100644
> --- a/fs/xfs/kmem.c
> +++ b/fs/xfs/kmem.c
> @@ -34,6 +34,8 @@ kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
> size_t kmsize = maxsize;
>
> while (!(ptr = vzalloc(kmsize))) {
> + if (kmsize == minsize)
> + break;
> if ((kmsize >>= 1) <= minsize)
> kmsize = minsize;
> }
> --
> 2.11.0
>
--
Michal Hocko
SUSE Labs
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Christoph Hellwig <hch@infradead.org> - 2017-03-02 01:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Xiong Zhou <xzhou@redhat.com> - 2017-03-02 06:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2017-03-02 07:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 09:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Xiong Zhou <xzhou@redhat.com> - 2017-03-02 10:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Bob Liu <liubo95@huawei.com> - 2017-03-02 07:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 12:50 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 13:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 13:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 13:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 14:10 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:40 +0100
[PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-02 16:50 +0100
[PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Michal Hocko <mhocko@kernel.org> - 2017-03-02 16:50 +0100
Re: [PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Christoph Hellwig <hch@lst.de> - 2017-03-02 17:00 +0100
Re: [PATCH 2/2] xfs: back off from kmem_zalloc_greedy if the task is killed Brian Foster <bfoster@redhat.com> - 2017-03-02 17:10 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Brian Foster <bfoster@redhat.com> - 2017-03-02 17:10 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Christoph Hellwig <hch@lst.de> - 2017-03-02 17:20 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-02 17:40 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-03-02 17:50 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Dave Chinner <david@fromorbit.com> - 2017-03-04 00:00 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-03-04 00:30 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Dave Chinner <david@fromorbit.com> - 2017-03-04 05:50 +0100
Re: [PATCH 1/2] xfs: allow kmem_zalloc_greedy to fail Michal Hocko <mhocko@kernel.org> - 2017-03-06 14:30 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 20:20 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Christoph Hellwig <hch@infradead.org> - 2017-03-02 19:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 20:20 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 16:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 18:40 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Brian Foster <bfoster@redhat.com> - 2017-03-02 15:00 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Michal Hocko <mhocko@kernel.org> - 2017-03-02 15:10 +0100
Re: mm allocation failure and hang when running xfstests generic/269 on xfs Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-03-02 17:00 +0100
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