On 02/21/2015 03:56 AM, Theodore Ts'o wrote:
> On Fri, Feb 20, 2015 at 09:49:34AM -0600, Eric Sandeen wrote:
>>> This mount option significantly reduces writes to the
>>> inode table for workloads that perform frequent random
>>> writes to preallocated files.
>> This seems like an overly specific description of a single workload out
>> of many which may benefit, but what do others think? "inode table" is also
>> fairly extN-specific.
> How about somethign like "This mount significantly reduces writes
> needed to update the inode's timestamps, especially mtime and actime.
What is "actime" in the preceding line? Should it be "ctime"?
> Examples of workloads where this could be a large win include frequent
> random writes to preallocated files, as well as cases where the
> MS_STRICTATIME mount option is enabled."?
I think some version of the following text could also usefully go
into the page, but...
> (The advantage of MS_STRICTATIME | MS_LAZYTIME is that stat system
> calls will return the correctly updated atime, but those atime updates
> won't get flushed to disk unless the inode needs to be updated for
> file system / data consistency reasons, or when the inode is pushed
> out of memory, or when the file system is unmounted.)
I find the wording of there a little confusing. Is the following
a correct rewrite:
The advantage of MS_STRICTATIME | MS_LAZYTIME is that stat(2)
will return the correctly updated atime, but the atime updates
will be flushed to disk only when (1) the inode needs to be
updated for filesystem / data consistency reasons or (2) the
inode is pushed out of memory, or (3) the filesystem is
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