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* O_NONBLOCK with Ext2/3
@ 2010-06-10 12:44 Yedire, Sandeep
  2010-06-11  0:50 ` Robert Hancock
  0 siblings, 1 reply; 3+ messages in thread
From: Yedire, Sandeep @ 2010-06-10 12:44 UTC (permalink / raw)
  To: linux-kernel

Hi All,
What is the effect  on filesystem blocks,data blocks if O_NONBLOCK
flag is used with a test application doing write to a file(64MB) on
NAND Flash.
Can any one please let me know
Regards,
Sandeep.Yedire

----------------------------------------------------------
T.Jefferson, 'Victory and defeat are each of the same price"

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: O_NONBLOCK with Ext2/3
  2010-06-10 12:44 O_NONBLOCK with Ext2/3 Yedire, Sandeep
@ 2010-06-11  0:50 ` Robert Hancock
  2010-06-11  4:34   ` Yedire, Sandeep
  0 siblings, 1 reply; 3+ messages in thread
From: Robert Hancock @ 2010-06-11  0:50 UTC (permalink / raw)
  To: Yedire, Sandeep; +Cc: linux-kernel

On 06/10/2010 06:44 AM, Yedire, Sandeep wrote:
> Hi All,
> What is the effect  on filesystem blocks,data blocks if O_NONBLOCK
> flag is used with a test application doing write to a file(64MB) on
> NAND Flash.
> Can any one please let me know
> Regards,
> Sandeep.Yedire

O_NONBLOCK doesn't do anything on regular files, as far as I'm aware. 
It's only useful on sockets, serial ports/TTYs, etc.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: O_NONBLOCK with Ext2/3
  2010-06-11  0:50 ` Robert Hancock
@ 2010-06-11  4:34   ` Yedire, Sandeep
  0 siblings, 0 replies; 3+ messages in thread
From: Yedire, Sandeep @ 2010-06-11  4:34 UTC (permalink / raw)
  To: Robert Hancock; +Cc: linux-kernel

On 11 June 2010 06:20, Robert Hancock <hancockrwd@gmail.com> wrote:
> On 06/10/2010 06:44 AM, Yedire, Sandeep wrote:
>>
>> Hi All,
>> What is the effect  on filesystem blocks,data blocks if O_NONBLOCK
>> flag is used with a test application doing write to a file(64MB) on
>> NAND Flash.
>> Can any one please let me know
>> Regards,
>> Sandeep.Yedire
>
> O_NONBLOCK doesn't do anything on regular files, as far as I'm aware. It's
> only useful on sockets, serial ports/TTYs, etc.
>

[Sandeep] In Ext2 fs, I have noticed many frequent updates to data
blocks as compared to without this flag. I also noticed Dirty page
limit (44MB max)  with O_NONBLOCK and 18 to 20MB max without this
flag. Because of this there is less Filesystem block updates with
O_NONBLOCK flag.

In case of Ext3, Dirty page limit is 18-20MB with or without this flag.
Its same with all modes of Ext3(data, ordered, writeback).

This is actually my concern.

Many Thanks,
Sandeep

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-06-11  4:34 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-06-10 12:44 O_NONBLOCK with Ext2/3 Yedire, Sandeep
2010-06-11  0:50 ` Robert Hancock
2010-06-11  4:34   ` Yedire, Sandeep

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