From: David Howells <dhowells@redhat.com>
To: Christoph Hellwig <hch@infradead.org>,
Nick Piggin <nickpiggin@yahoo.com.au>
Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org,
nfsv4@linux-nfs.org, viro@zeniv.linux.org.uk,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 22/43] CacheFiles: Add a hook to write a single page of data to an inode [ver #46]
Date: Fri, 03 Apr 2009 14:41:48 +0100 [thread overview]
Message-ID: <10789.1238766108@redhat.com> (raw)
In-Reply-To: <29524.1238696291@redhat.com>
David Howells <dhowells@redhat.com> wrote:
> + data = kmap(page);
> + old_fs = get_fs();
> + set_fs(KERNEL_DS);
> + ret = file->f_op->write(
> + file, (const void __user *) data, PAGE_SIZE,
> + &pos);
> + set_fs(old_fs);
> + kunmap(page);
Hmmm... Now I've thought about it some more, I'm not sure this is a good
idea. Can this run a system out of kmap() resources? These are run by a
dynamic thread pool, where each thread in the pool can do a kmap and issue a
write, but the write may get delayed for a significant amount of time for a
number of reasons - such as block allocation, data fetching and memory
allocation.
David
next prev parent reply other threads:[~2009-04-03 13:41 UTC|newest]
Thread overview: 86+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-01 23:03 [PATCH 00/43] Permit filesystem local caching [ver #46] David Howells
2009-04-01 23:03 ` [PATCH 01/43] Create a dynamically sized pool of threads for doing very slow work items " David Howells
2009-04-01 23:03 ` [PATCH 02/43] Make slow-work thread pool actually dynamic " David Howells
2009-04-01 23:03 ` [PATCH 03/43] Make the slow work pool configurable " David Howells
2009-04-01 23:03 ` [PATCH 04/43] Document the slow work thread pool " David Howells
2009-04-01 23:03 ` [PATCH 05/43] FS-Cache: Release page->private after failed readahead " David Howells
2009-04-02 13:51 ` Nick Piggin
2009-04-02 14:21 ` David Howells
2009-04-02 17:17 ` Rik van Riel
2009-04-01 23:03 ` [PATCH 06/43] FS-Cache: Recruit a couple of page flags for cache management " David Howells
2009-04-02 13:55 ` Nick Piggin
2009-04-02 14:36 ` David Howells
2009-04-02 15:25 ` Nick Piggin
2009-04-02 15:51 ` David Howells
2009-04-02 16:15 ` Nick Piggin
2009-04-02 16:53 ` Nick Piggin
2009-04-02 17:09 ` David Howells
2009-04-02 17:31 ` Nick Piggin
2009-04-02 17:40 ` David Howells
2009-04-02 18:14 ` Nick Piggin
2009-04-02 19:19 ` Trond Myklebust
2009-04-03 1:11 ` David Howells
2009-04-02 16:48 ` What I mean by a 'netfs' when dealing with FS-Cache David Howells
2009-04-02 17:06 ` David Howells
2009-04-02 18:23 ` [PATCH 06/43] FS-Cache: Recruit a couple of page flags for cache management [ver #46] Rik van Riel
2009-04-01 23:03 ` [PATCH 07/43] FS-Cache: Add the FS-Cache netfs API and documentation " David Howells
2009-04-01 23:04 ` [PATCH 08/43] FS-Cache: Add the FS-Cache cache backend " David Howells
2009-04-01 23:04 ` [PATCH 09/43] FS-Cache: Add main configuration option, module entry points and debugging " David Howells
2009-04-01 23:04 ` [PATCH 10/43] FS-Cache: Add use of /proc and presentation of statistics " David Howells
2009-04-01 23:04 ` [PATCH 11/43] FS-Cache: Root index definition " David Howells
2009-04-01 23:04 ` [PATCH 12/43] FS-Cache: Add cache tag handling " David Howells
2009-04-01 23:04 ` [PATCH 13/43] FS-Cache: Add cache management " David Howells
2009-04-01 23:04 ` [PATCH 14/43] FS-Cache: Provide a slab for cookie allocation " David Howells
2009-04-01 23:04 ` [PATCH 15/43] FS-Cache: Add netfs registration " David Howells
2009-04-01 23:04 ` [PATCH 16/43] FS-Cache: Bit waiting helpers " David Howells
2009-04-01 23:04 ` [PATCH 17/43] FS-Cache: Object management state machine " David Howells
2009-04-01 23:04 ` [PATCH 18/43] FS-Cache: Implement the cookie management part of the netfs API " David Howells
2009-04-01 23:04 ` [PATCH 19/43] FS-Cache: Add and document asynchronous operation handling " David Howells
2009-04-01 23:05 ` [PATCH 20/43] FS-Cache: Implement data I/O part of netfs API " David Howells
2009-04-01 23:05 ` [PATCH 21/43] CacheFiles: Be consistent about the use of mapping vs file->f_mapping in Ext3 " David Howells
2009-04-02 18:52 ` Rik van Riel
2009-04-01 23:05 ` [PATCH 22/43] CacheFiles: Add a hook to write a single page of data to an inode " David Howells
2009-04-02 14:00 ` Nick Piggin
2009-04-02 14:55 ` David Howells
2009-04-02 15:32 ` Nick Piggin
2009-04-02 16:37 ` Christoph Hellwig
2009-04-02 16:47 ` Nick Piggin
2009-04-02 16:55 ` Christoph Hellwig
2009-04-02 17:07 ` Nick Piggin
2009-04-02 17:26 ` Jan Kara
2009-04-02 17:22 ` David Howells
2009-04-02 18:18 ` David Howells
2009-04-02 22:44 ` David Howells
2009-04-03 13:41 ` David Howells [this message]
2009-04-02 16:02 ` David Howells
2009-04-02 15:32 ` Peter Staubach
2009-04-02 16:03 ` David Howells
2009-04-02 18:48 ` Rik van Riel
2009-04-01 23:05 ` [PATCH 23/43] CacheFiles: Permit the page lock state to be monitored " David Howells
2009-04-02 15:37 ` Nick Piggin
2009-04-02 16:14 ` David Howells
2009-04-02 16:35 ` Nick Piggin
2009-04-02 17:05 ` David Howells
2009-04-02 18:03 ` Nick Piggin
2009-04-02 18:51 ` Rik van Riel
2009-04-01 23:05 ` [PATCH 24/43] CacheFiles: Export things for CacheFiles " David Howells
2009-04-02 18:53 ` Rik van Riel
2009-04-01 23:05 ` [PATCH 25/43] CacheFiles: A cache that backs onto a mounted filesystem " David Howells
2009-04-01 23:05 ` [PATCH 26/43] FS-Cache: Make kAFS use FS-Cache " David Howells
2009-04-01 23:05 ` [PATCH 27/43] NFS: Add comment banners to some NFS functions " David Howells
2009-04-01 23:05 ` [PATCH 28/43] NFS: Add FS-Cache option bit and debug bit " David Howells
2009-04-01 23:05 ` [PATCH 29/43] NFS: Permit local filesystem caching to be enabled for NFS " David Howells
2009-04-01 23:05 ` [PATCH 30/43] NFS: Register NFS for caching and retrieve the top-level index " David Howells
2009-04-01 23:06 ` [PATCH 31/43] NFS: Define and create server-level objects " David Howells
2009-04-01 23:06 ` [PATCH 32/43] NFS: Define and create superblock-level " David Howells
2009-04-01 23:06 ` [PATCH 33/43] NFS: Define and create inode-level cache " David Howells
2009-04-01 23:06 ` [PATCH 34/43] NFS: Use local disk inode cache " David Howells
2009-04-01 23:06 ` [PATCH 35/43] NFS: Invalidate FsCache page flags when cache removed " David Howells
2009-04-01 23:06 ` [PATCH 36/43] NFS: Add some new I/O counters for FS-Cache doing things for NFS " David Howells
2009-04-01 23:06 ` [PATCH 37/43] NFS: FS-Cache page management " David Howells
2009-04-01 23:06 ` [PATCH 38/43] NFS: Add read context retention for FS-Cache to call back with " David Howells
2009-04-01 23:06 ` [PATCH 39/43] NFS: nfs_readpage_async() needs to be accessible as a fallback for local caching " David Howells
2009-04-01 23:06 ` [PATCH 40/43] NFS: Read pages from FS-Cache into an NFS inode " David Howells
2009-04-01 23:06 ` [PATCH 41/43] NFS: Store pages from an NFS inode into a local cache " David Howells
2009-04-01 23:06 ` [PATCH 42/43] NFS: Display local caching state " David Howells
2009-04-01 23:07 ` [PATCH 43/43] NFS: Add mount options to enable local caching on NFS " David Howells
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