Messages in this thread | | | From | Khazhy Kumykov <> | Date | Fri, 18 Mar 2022 18:45:04 -0700 | Subject | Re: [PATCH RFC] nfsd: avoid recursive locking through fsnotify |
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On Fri, Mar 18, 2022 at 5:36 PM Trond Myklebust <trondmy@hammerspace.com> wrote: > > Isn't that stack trace showing a slab direct reclaim, and not a > filesystem writeback situation? > > Does memalloc_nofs_save()/restore() really fix this problem? It seems > to me that it cannot, particularly since knfsd is not a filesystem, and > so does not ever handle writeback of dirty pages.
Ah you're right. An alternative would be delaying the destroy_mark, which I am noticing now that, on mainline, the shrinker calls nfsd_file_dispose_list_delayed, something missing from the version of 5.4 I was looking at.
To my reading 9542e6a643fc6 ("nfsd: Containerise filecache laundrette") should have the effect of fixing this deadlock (and the message does explicitly call out notifier deadlocks) - maybe something to send towards stable? > > > Cc: the linux-mm mailing list in search of answers to the above 2 > questions. > > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@hammerspace.com > > [unhandled content-type:application/pkcs7-signature] | |