2001-10-08 17:39:50

by Louis E Garcia II

[permalink] [raw]
Subject: linux-2.4.10-acX

Has Alan's tree been fully merged with Linus's?? Or are their bits in
Linus's tree that is not in Alan's?

Louis





2001-10-08 18:01:40

by Alan

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

> Has Alan's tree been fully merged with Linus's?? Or are their bits in
> Linus's tree that is not in Alan's?

There are measurable differences between the two trees. Notably

- Linus uses the Andrea VM in 2.4.10
-ac uses the Riel VM in 2.4.10-ac

The -ac tree also has the following major additions

- Platform support for x86_64, usermode linux , etc
- 32bit uid safe quota
- Ext3 file system
- PnPBIOS support
- Various PPro and Pentium workarounds
- Simple boot flag
- Faster x86 syscall path
- PPPoATM
- Elevator flow control
- DRM 4.0 and 4.1 support not just 4.1 (ie XFree 4.0.x works)
- CMS file system
- Intermezzo file system
- isofs compression

and drivers for

- IB700
- IBM Mwave
- Lots more MTD devices
- SA1100 PCMCIA
- Various USB toys

and then lots of bug fixes

Much of that will go on to Linus. Some he has refused (faster syscall path,
elevator flow control, ..). It takes time to feed stuff on and often I want
to test it in -ac first. Because so much changed in 2.4.10/11pre it's now
getting very hard to merge a lot of the fixes like the truncate standards
compliance stuff so they may not make Linus tree until 2.5


Alan

2001-10-08 18:21:00

by Louis E Garcia II

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

Has raw/block I/O changes from linus 2.4.10 been merged?

Louis

On Mon, 2001-10-08 at 14:07, Alan Cox wrote:
> > Has Alan's tree been fully merged with Linus's?? Or are their bits in
> > Linus's tree that is not in Alan's?
>
> There are measurable differences between the two trees. Notably
>
> - Linus uses the Andrea VM in 2.4.10
> -ac uses the Riel VM in 2.4.10-ac
>
> The -ac tree also has the following major additions
>
> - Platform support for x86_64, usermode linux , etc
> - 32bit uid safe quota
> - Ext3 file system
> - PnPBIOS support
> - Various PPro and Pentium workarounds
> - Simple boot flag
> - Faster x86 syscall path
> - PPPoATM
> - Elevator flow control
> - DRM 4.0 and 4.1 support not just 4.1 (ie XFree 4.0.x works)
> - CMS file system
> - Intermezzo file system
> - isofs compression
>
> and drivers for
>
> - IB700
> - IBM Mwave
> - Lots more MTD devices
> - SA1100 PCMCIA
> - Various USB toys
>
> and then lots of bug fixes
>
> Much of that will go on to Linus. Some he has refused (faster syscall path,
> elevator flow control, ..). It takes time to feed stuff on and often I want
> to test it in -ac first. Because so much changed in 2.4.10/11pre it's now
> getting very hard to merge a lot of the fixes like the truncate standards
> compliance stuff so they may not make Linus tree until 2.5
>
>
> Alan



2001-10-08 18:23:40

by Alan

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

> Has raw/block I/O changes from linus 2.4.10 been merged?

No. There were certain bits of 2.5^H4.10 that I took one look at and threw
out for the moment as unsafe for a stable tree - the page cache block
device and O_DIRECT stuff included.

2.4.11pre seems to back some of that out too.

2001-10-08 21:22:49

by Robert Love

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

On Mon, 2001-10-08 at 14:07, Alan Cox wrote:

> Much of that will go on to Linus. Some he has refused (faster syscall path,
> elevator flow control, ..). It takes time to feed stuff on and often I want
> to test it in -ac first. Because so much changed in 2.4.10/11pre it's now
> getting very hard to merge a lot of the fixes like the truncate standards
> compliance stuff so they may not make Linus tree until 2.5

What are Linus's complaints about the faster syscall path improvement?

Robert Love

2001-10-08 21:26:19

by Alan

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

> > getting very hard to merge a lot of the fixes like the truncate standards
> > compliance stuff so they may not make Linus tree until 2.5
>
> What are Linus's complaints about the faster syscall path improvement?

He insisted it wouldnt make it any faster. Of course rdtsc and profiling
counters of locked cycles show otherwise..

2001-10-08 22:28:15

by Mike Fedyk

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

On Mon, Oct 08, 2001 at 07:07:12PM +0100, Alan Cox wrote:
> > Has Alan's tree been fully merged with Linus's?? Or are their bits in
> > Linus's tree that is not in Alan's?
>
> There are measurable differences between the two trees. Notably
>
> - Linus uses the Andrea VM in 2.4.10
> -ac uses the Riel VM in 2.4.10-ac
>
> The -ac tree also has the following major additions
>
> - Elevator flow control

Where can I find more information on this?

Mike

2001-10-08 22:31:45

by Alan

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

> > - Elevator flow control
>
> Where can I find more information on this?

Read the ll_rw_blk diff. Basically it tries to avoid too many locked buffers
clogging up memory and killing the box. I'm not totally sure its the
right approach

2001-10-09 00:03:23

by Linus Torvalds

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

In article <[email protected]>,
Alan Cox <[email protected]> wrote:
>> > getting very hard to merge a lot of the fixes like the truncate standards
>> > compliance stuff so they may not make Linus tree until 2.5
>>
>> What are Linus's complaints about the faster syscall path improvement?
>
>He insisted it wouldnt make it any faster. Of course rdtsc and profiling
>counters of locked cycles show otherwise..

No, I insist that it doesn't make things _noticeably_ faster (a segment
load is something like 12 cycles on a PII), and doing it complicates the
return path unnecessarily for the default case.

I seriously doubt you've (or anybody else) measured it with rdtsc or
profiling: what you call the "fast path" is never taken on regular
system calls, only on nested calls where we return to the kernel. How
many of those have you ever seen?

In short, has _anybody_ EVER seen any actual improvement from this ugly
"optimization"?

Linus

2001-10-09 00:22:26

by Greg KH

[permalink] [raw]
Subject: Re: linux-2.4.10-acX

On Mon, Oct 08, 2001 at 07:07:12PM +0100, Alan Cox wrote:
> - Various USB toys

I've been working on sending changes to Linus to reduce the differences
in the USB trees. This processes isn't finished yet.

thanks,

greg k-h