From: "Benjamin Coddington" <bcodding@redhat.com>
To: "Trond Myklebust" <trondmy@hammerspace.com>
Cc: linux-nfs@vger.kernel.org, dwysocha@redhat.com
Subject: Re: [PATCH v5 00/22] Readdir enhancements
Date: Thu, 12 Nov 2020 14:09:42 -0500 [thread overview]
Message-ID: <DD8B2AD2-34BF-4751-A01A-3E10677EB8E7@redhat.com> (raw)
In-Reply-To: <6eed4c13be095a979b31b98668bf64f60ad0be51.camel@hammerspace.com>
On 12 Nov 2020, at 14:04, Trond Myklebust wrote:
> On Thu, 2020-11-12 at 13:39 -0500, Benjamin Coddington wrote:
>>
>>
>> On 12 Nov 2020, at 13:26, Trond Myklebust wrote:
>>
>>> On Thu, 2020-11-12 at 16:51 +0000, Trond Myklebust wrote:
>>>>
>>>> I was going to ask you if perhaps reverting Scott's commit
>>>> 07b5ce8ef2d8
>>>> ("NFS: Make nfs_readdir revalidate less often") might help here?
>>>> My thinking is that will trigger more cache invalidations when
>>>> the
>>>> directory is changing underneath us, and will now trigger
>>>> uncached
>>>> readdir in those situations.
>>>>
>>>>>
>>>
>>> IOW, the suggestion would be to apply something like the following
>>> on
>>> top of the existing readdir patchset:
>>
>> I'm all for this approach, but - I'm rarely seeing the mapping-
>>> nrpages == 0
>> since the cache is dropped by a process in nfs_readdir() that
>> immediately
>> starts filling the cache again.
>
> That's why I moved the check in readdir_search_pagecache. Unless that
> process has set desc->dir_cookie == 0, then that should prevent the
> refilling.
My pathological benchmarking does send another process in with
desc->dir_cookie == 0.
I'm doing fork(), while(getdents) every second with acdirmin=1 and a listing
that takes longer than 1 second to complete uncached, while touching the
directory every second.
Ben
next prev parent reply other threads:[~2020-11-12 19:09 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 21:37 [PATCH v5 00/22] Readdir enhancements trondmy
2020-11-10 21:37 ` [PATCH v5 01/22] NFS: Remove unnecessary inode locking in nfs_llseek_dir() trondmy
2020-11-10 21:37 ` [PATCH v5 02/22] NFS: Remove unnecessary inode lock in nfs_fsync_dir() trondmy
2020-11-10 21:37 ` [PATCH v5 03/22] NFSv4.2: condition READDIR's mask for security label based on LSM state trondmy
2020-11-10 21:37 ` [PATCH v5 04/22] NFS: Ensure contents of struct nfs_open_dir_context are consistent trondmy
2020-11-10 21:37 ` [PATCH v5 05/22] NFS: Clean up readdir struct nfs_cache_array trondmy
2020-11-10 21:37 ` [PATCH v5 06/22] NFS: Clean up nfs_readdir_page_filler() trondmy
2020-11-10 21:37 ` [PATCH v5 07/22] NFS: Clean up directory array handling trondmy
2020-11-10 21:37 ` [PATCH v5 08/22] NFS: Don't discard readdir results trondmy
2020-11-10 21:37 ` [PATCH v5 09/22] NFS: Remove unnecessary kmap in nfs_readdir_xdr_to_array() trondmy
2020-11-10 21:37 ` [PATCH v5 10/22] NFS: Replace kmap() with kmap_atomic() in nfs_readdir_search_array() trondmy
2020-11-10 21:37 ` [PATCH v5 11/22] NFS: Simplify struct nfs_cache_array_entry trondmy
2020-11-10 21:37 ` [PATCH v5 12/22] NFS: Support larger readdir buffers trondmy
2020-11-10 21:37 ` [PATCH v5 13/22] NFS: More readdir cleanups trondmy
2020-11-10 21:37 ` [PATCH v5 14/22] NFS: nfs_do_filldir() does not return a value trondmy
2020-11-10 21:37 ` [PATCH v5 15/22] NFS: Reduce readdir stack usage trondmy
2020-11-10 21:37 ` [PATCH v5 16/22] NFS: Cleanup to remove nfs_readdir_descriptor_t typedef trondmy
2020-11-10 21:37 ` [PATCH v5 17/22] NFS: Allow the NFS generic code to pass in a verifier to readdir trondmy
2020-11-10 21:37 ` [PATCH v5 18/22] NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls trondmy
2020-11-10 21:37 ` [PATCH v5 19/22] NFS: Improve handling of directory verifiers trondmy
2020-11-10 21:37 ` [PATCH v5 20/22] NFS: Optimisations for monotonically increasing readdir cookies trondmy
2020-11-10 21:37 ` [PATCH v5 21/22] NFS: Reduce number of RPC calls when doing uncached readdir trondmy
2020-11-10 21:37 ` [PATCH v5 22/22] NFS: Do uncached readdir when we're seeking a cookie in an empty page cache trondmy
2020-11-11 22:15 ` [PATCH v5 00/22] Readdir enhancements David Wysochanski
2020-11-12 11:41 ` David Wysochanski
2020-11-12 15:34 ` Guy Keren
2020-11-12 16:54 ` Trond Myklebust
2020-11-12 16:51 ` Trond Myklebust
2020-11-12 18:26 ` Trond Myklebust
2020-11-12 18:39 ` Benjamin Coddington
2020-11-12 18:49 ` Benjamin Coddington
2020-11-12 19:04 ` Trond Myklebust
2020-11-12 19:09 ` Benjamin Coddington [this message]
2020-11-12 20:23 ` Benjamin Coddington
2020-11-13 11:09 ` Mkrtchyan, Tigran
2020-11-14 13:32 ` David Wysochanski
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