From: Trond Myklebust <trondmy@hammerspace.com>
To: "guy@vastdata.com" <guy@vastdata.com>,
"dwysocha@redhat.com" <dwysocha@redhat.com>
Cc: "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"trondmy@kernel.org" <trondmy@kernel.org>
Subject: Re: [PATCH v5 00/22] Readdir enhancements
Date: Thu, 12 Nov 2020 16:54:39 +0000 [thread overview]
Message-ID: <fbc830f41e90c510adef43e13c4463add305f6a9.camel@hammerspace.com> (raw)
In-Reply-To: <CAENext7G47KvYO3q0_7g3KUX+QxQs3G17nuqs=Npsg2RBPdX7g@mail.gmail.com>
On Thu, 2020-11-12 at 17:34 +0200, Guy Keren wrote:
> just a general question: since the cache seems to cause many problems
> when dealing with very large directories, and since all solutions
> proposed until now don't seem to fully solve those problems, won't an
> approach such as "if the directory entries count exceeded X - stop
> using the cache completely" - where X is proportional to the size of
> the directory entries cache size limit - make the code simpler, and
> less prone to bugs of this sort?
>
> i *think* we can understand that for a directory with millions of
> files, we'll not have efficient caching on the client side, while
> limiting ourselves to reasonable RAM consumption?
>
Again, I disagree.
If you have a mostly-read directory with millions of files (e.g. data
pool) and lots of processes searching, then caching is both useful and
appropriate.
>
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com
next prev parent reply other threads:[~2020-11-12 16:54 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 [this message]
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
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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