Cancel Safe queues for paging i/o?

Hi all,
Sometimes I need to queue paging I/O read/write IRPs (not paging
FILE i/o, just paging i/o to normal files) and complete them asychronously.
In general, should I have to worry about the IRPs being cancelled or using
cancel safe queues to handle these IRPs in this scenario?

Thanks,
Matt

For now long will you keep the IRPs in the queue?

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Matthew N. White”
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, July 14, 2004 7:34 PM
Subject: [ntfsd] Cancel Safe queues for paging i/o?

> Hi all,
> Sometimes I need to queue paging I/O read/write IRPs (not paging
> FILE i/o, just paging i/o to normal files) and complete them asychronously.
> In general, should I have to worry about the IRPs being cancelled or using
> cancel safe queues to handle these IRPs in this scenario?
>
> Thanks,
> Matt
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

Well, I guess my answer to that would be “not long”. I just need to queue
them sometimes to serialize some operations, so the longest they would be
queued is until a previous IRP completes.

Matt

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S. Shatskih
Sent: Wednesday, July 14, 2004 11:35 AM
To: Windows File Systems Devs Interest List
Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?

For now long will you keep the IRPs in the queue?

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Matthew N. White”
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, July 14, 2004 7:34 PM
Subject: [ntfsd] Cancel Safe queues for paging i/o?

> Hi all,
> Sometimes I need to queue paging I/O read/write IRPs (not paging
> FILE i/o, just paging i/o to normal files) and complete them
asychronously.
> In general, should I have to worry about the IRPs being cancelled or using
> cancel safe queues to handle these IRPs in this scenario?
>
> Thanks,
> Matt
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com


Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@bitarmor.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

Then probably no need in cancellation support.

Cancellation is a must if the IRPs are queued for indefinite time - like
the serial port or socket reads.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Matthew N. White”
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, July 14, 2004 7:55 PM
Subject: RE: [ntfsd] Cancel Safe queues for paging i/o?

> Well, I guess my answer to that would be “not long”. I just need to queue
> them sometimes to serialize some operations, so the longest they would be
> queued is until a previous IRP completes.
>
> Matt
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S. Shatskih
> Sent: Wednesday, July 14, 2004 11:35 AM
> To: Windows File Systems Devs Interest List
> Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?
>
> For now long will you keep the IRPs in the queue?
>
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
>
> ----- Original Message -----
> From: “Matthew N. White”
> To: “Windows File Systems Devs Interest List”
> Sent: Wednesday, July 14, 2004 7:34 PM
> Subject: [ntfsd] Cancel Safe queues for paging i/o?
>
>
> > Hi all,
> > Sometimes I need to queue paging I/O read/write IRPs (not paging
> > FILE i/o, just paging i/o to normal files) and complete them
> asychronously.
> > In general, should I have to worry about the IRPs being cancelled or using
> > cancel safe queues to handle these IRPs in this scenario?
> >
> > Thanks,
> > Matt
> >
> >
> > —
> > Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
> >
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@bitarmor.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com

Making paging read/writes cancellable doesn’t mean much, because they
are never cancelled. They are either synchronous i/o’s that the kernel
waits for in a non-awakeable way, or async writes that are in a system
thread - and are never cancelled.

The important thing is to just not hold onto paging i/o’s - especially
the paging writes that are freeing up pages so there’s enough memory to
go around.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S. Shatskih
Sent: Wednesday, July 14, 2004 9:00 AM
To: Windows File Systems Devs Interest List
Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?

Then probably no need in cancellation support.

Cancellation is a must if the IRPs are queued for indefinite time -
like the serial port or socket reads.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Matthew N. White”
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, July 14, 2004 7:55 PM
Subject: RE: [ntfsd] Cancel Safe queues for paging i/o?

> Well, I guess my answer to that would be “not long”. I just need to
queue
> them sometimes to serialize some operations, so the longest they would
be
> queued is until a previous IRP completes.
>
> Matt
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S.
Shatskih
> Sent: Wednesday, July 14, 2004 11:35 AM
> To: Windows File Systems Devs Interest List
> Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?
>
> For now long will you keep the IRPs in the queue?
>
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
>
> ----- Original Message -----
> From: “Matthew N. White”
> To: “Windows File Systems Devs Interest List”
> Sent: Wednesday, July 14, 2004 7:34 PM
> Subject: [ntfsd] Cancel Safe queues for paging i/o?
>
>
> > Hi all,
> > Sometimes I need to queue paging I/O read/write IRPs (not paging
> > FILE i/o, just paging i/o to normal files) and complete them
> asychronously.
> > In general, should I have to worry about the IRPs being cancelled or
using
> > cancel safe queues to handle these IRPs in this scenario?
> >
> > Thanks,
> > Matt
> >
> >
> > —
> > Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
> >
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> > To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@bitarmor.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com
> To unsubscribe send a blank email to xxxxx@lists.osr.com


Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com

MM has an elegant and simple way to tell a file system that it has held
on to too many paging write operations - the NO_PAGES_AVAILABLE stop
code. Most of us that have done file systems long enough have seen this
at some point.

Regards,

Tony

Tony Mason
Consulting Partner
OSR Open Systems Resources, Inc.
http://www.osr.com

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Ravisankar Pudipeddi
Sent: Wednesday, July 14, 2004 4:40 PM
To: ntfsd redirect
Subject: RE: [ntfsd] Cancel Safe queues for paging i/o?

Making paging read/writes cancellable doesn’t mean much, because they
are never cancelled. They are either synchronous i/o’s that the kernel
waits for in a non-awakeable way, or async writes that are in a system
thread - and are never cancelled.

The important thing is to just not hold onto paging i/o’s - especially
the paging writes that are freeing up pages so there’s enough memory to
go around.

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S. Shatskih
Sent: Wednesday, July 14, 2004 9:00 AM
To: Windows File Systems Devs Interest List
Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?

Then probably no need in cancellation support.

Cancellation is a must if the IRPs are queued for indefinite time -
like the serial port or socket reads.

Maxim Shatskih, Windows DDK MVP
StorageCraft Corporation
xxxxx@storagecraft.com
http://www.storagecraft.com

----- Original Message -----
From: “Matthew N. White”
To: “Windows File Systems Devs Interest List”
Sent: Wednesday, July 14, 2004 7:55 PM
Subject: RE: [ntfsd] Cancel Safe queues for paging i/o?

> Well, I guess my answer to that would be “not long”. I just need to
queue
> them sometimes to serialize some operations, so the longest they would
be
> queued is until a previous IRP completes.
>
> Matt
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com] On Behalf Of Maxim S.
Shatskih
> Sent: Wednesday, July 14, 2004 11:35 AM
> To: Windows File Systems Devs Interest List
> Subject: Re: [ntfsd] Cancel Safe queues for paging i/o?
>
> For now long will you keep the IRPs in the queue?
>
> Maxim Shatskih, Windows DDK MVP
> StorageCraft Corporation
> xxxxx@storagecraft.com
> http://www.storagecraft.com
>
>
> ----- Original Message -----
> From: “Matthew N. White”
> To: “Windows File Systems Devs Interest List”
> Sent: Wednesday, July 14, 2004 7:34 PM
> Subject: [ntfsd] Cancel Safe queues for paging i/o?
>
>
> > Hi all,
> > Sometimes I need to queue paging I/O read/write IRPs (not paging
> > FILE i/o, just paging i/o to normal files) and complete them
> asychronously.
> > In general, should I have to worry about the IRPs being cancelled or
using
> > cancel safe queues to handle these IRPs in this scenario?
> >
> > Thanks,
> > Matt
> >
> >
> > —
> > Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
> >
> > You are currently subscribed to ntfsd as: xxxxx@storagecraft.com To
> > unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
> https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@bitarmor.com To
> unsubscribe send a blank email to xxxxx@lists.osr.com
>
>
> —
> Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17
>
> You are currently subscribed to ntfsd as: xxxxx@storagecraft.com To
> unsubscribe send a blank email to xxxxx@lists.osr.com


Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com


Questions? First check the IFS FAQ at
https://www.osronline.com/article.cfm?id=17

You are currently subscribed to ntfsd as: xxxxx@osr.com To unsubscribe
send a blank email to xxxxx@lists.osr.com