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From: m on 18 Feb 2010 18:33
IMHO, many anti-virus programs are worse than the viruses they are meant to
defend against. Usually, the 'disabled' mode is just an auto-allow all
mode, and the performance penalties still apply. Some products don't even
uninstall cleanly and the only way to remove them is to reinstall the OS.

But besides the possibility of a bad AV program, here are a few other things
to consider:
- check the disk type (ie SAS, SATA, IDE, SCSI etc.) since some of the
in-box drivers (esp IDE) are known to cause performance issues
- check the controller and bus topology of the machines. Many machines will
have SATA disks connected using the AHCI controller built into the Intel
supplied south bridge, but if there are several bridges in play, or other
non-standard HW, then there may be driver or HW effects that come into play
- does defragmenting the disk, or writing to another clean disk on this
machine affect the result? If the available space is low, and the FS
heavily fragmented, then performance will suffer
- Are the disks are formatted with NTFS, or is there FAT32? While XP can
work with FAT, the performance will differ significantly in many cases
- are the versions of the CRT in use on all machines identical (as they
would be if it were statically linked)?

Also, in the interval while it appears to hang, do the process IO counters
increase? Do the system process IO counters increase? This info will help
you to determine if the delay that you are seeing is caused by cache
flushing or something else.

"Rahul" <rsharma.champ(a)gmail.com> wrote in message
news:71165977-5bb4-4e8f-a3cc-631b969941d4(a)k5g2000pra.googlegroups.com...
> On Feb 18, 5:51 pm, "Francois PIETTE" <fpie...(a)newsgroups.nospam>
> wrote:
>> > My application writes data in a file using fopen/fwrite/fclose and
>> > immediately after fclose I try to open the same file using. the
>> > windows CreateFile() function.
>> > In one of my machine all are very fast and the total process finishes
>> > in < 4 seconds.
>>
>> > But on one machine fclose itself takes around 15 seconds, I tried
>> > using setbuf(fp, NULL) and calling fflush(fp) after every write, but
>> > then also fclose took 15 seconds. I also tried using the low level
>> > functions _open, _close etc. but there also the _close took 15 second
>> > of time.
>>
>> > What is more strange to me is that there is one more machine on which
>> > fopen/fwrite/fclose works quite fast but the last CreateFile() call
>> > takes > 15 seconds to open the same file.
>>
>> Look for so called "security product". For example an antivirus program
>> may
>> be buggy and tak a lot of time processing the data.
>> Also have a look at disk fragmentation and bad sectors.
>>
>> On the computer experiencing slow response, does other software suffer
>> from
>> the same problem or is this specific to one application ?
>>
>> --
>> francois.pie...(a)overbyte.be
>> The author of the freeware multi-tier middleware MidWare
>> The author of the freeware Internet Component Suite
>> (ICS)http://www.overbyte.be
>
> Hi Francois,
>
> I do not know about other softwares, but the disk is highly
> fragmented. however for small files the fclose/ CreateFile works
> pretty fast. the problem happens whiel trying to write > 5 MB files.
> and I always disable the antivirus before doing any performance test
> on the machines.
>
> Thanks & Regards
>
>
From: Tom Serface on 19 Feb 2010 00:25
If you are doing the same test with fopen vs. CreateFile on the same machine
under the same conditions I would expect CreateFile to be faster if anything
at all. It might be in the way you are opening CreateFile. Maybe you could
list the code where you do the call to open the file...

Tom

"Rahul" <rsharma.champ(a)gmail.com> wrote in message
news:71165977-5bb4-4e8f-a3cc-631b969941d4(a)k5g2000pra.googlegroups.com...
On Feb 18, 5:51 pm, "Francois PIETTE" <fpie...(a)newsgroups.nospam>
wrote:
> > My application writes data in a file using fopen/fwrite/fclose and
> > immediately after fclose I try to open the same file using. the
> > windows CreateFile() function.
> > In one of my machine all are very fast and the total process finishes
> > in < 4 seconds.
>
> > But on one machine fclose itself takes around 15 seconds, I tried
> > using setbuf(fp, NULL) and calling fflush(fp) after every write, but
> > then also fclose took 15 seconds. I also tried using the low level
> > functions _open, _close etc. but there also the _close took 15 second
> > of time.
>
> > What is more strange to me is that there is one more machine on which
> > fopen/fwrite/fclose works quite fast but the last CreateFile() call
> > takes > 15 seconds to open the same file.
>
> Look for so called "security product". For example an antivirus program
> may
> be buggy and tak a lot of time processing the data.
> Also have a look at disk fragmentation and bad sectors.
>
> On the computer experiencing slow response, does other software suffer
> from
> the same problem or is this specific to one application ?
>
> --
> francois.pie...(a)overbyte.be
> The author of the freeware multi-tier middleware MidWare
> The author of the freeware Internet Component Suite
> (ICS)http://www.overbyte.be

Hi Francois,

I do not know about other softwares, but the disk is highly
fragmented. however for small files the fclose/ CreateFile works
pretty fast. the problem happens whiel trying to write > 5 MB files.
and I always disable the antivirus before doing any performance test
on the machines.

Thanks & Regards



From: Rahul on 19 Feb 2010 00:51
On Feb 19, 10:25 am, "Tom Serface" <tserf...(a)msn.com> wrote:
> If you are doing the same test with fopen vs. CreateFile on the same machine
> under the same conditions I would expect CreateFile to be faster if anything
> at all.  It might be in the way you are opening CreateFile.  Maybe you could
> list the code where you do the call to open the file...
>
> Tom
>
> "Rahul" <rsharma.ch...(a)gmail.com> wrote in message
>
> news:71165977-5bb4-4e8f-a3cc-631b969941d4(a)k5g2000pra.googlegroups.com...
> On Feb 18, 5:51 pm, "Francois PIETTE" <fpie...(a)newsgroups.nospam>
> wrote:
>
>
>
>
>
> > > My application writes data in a file using fopen/fwrite/fclose and
> > > immediately after fclose I try to open the same file using. the
> > > windows CreateFile() function.
> > > In one of my machine all are very fast and the total process finishes
> > > in < 4 seconds.
>
> > > But on one machine fclose itself takes around 15 seconds, I tried
> > > using setbuf(fp, NULL) and calling fflush(fp) after every write, but
> > > then also fclose took 15 seconds. I also tried using the low level
> > > functions _open, _close etc. but there also the _close took 15 second
> > > of time.
>
> > > What is more strange to me is that there is one more machine on which
> > > fopen/fwrite/fclose works quite fast but the last CreateFile() call
> > > takes > 15 seconds to open the same file.
>
> > Look for so called "security product". For example an antivirus program
> > may
> > be buggy and tak a lot of time processing the data.
> > Also have a look at disk fragmentation and bad sectors.
>
> > On the computer experiencing slow response, does other software suffer
> > from
> > the same problem or is this specific to one application ?
>
> > --
> > francois.pie...(a)overbyte.be
> > The author of the freeware multi-tier middleware MidWare
> > The author of the freeware Internet Component Suite
> > (ICS)http://www.overbyte.be
>
> Hi Francois,
>
> I do not know about other softwares, but the disk is highly
> fragmented. however for small files the fclose/ CreateFile works
> pretty fast. the problem happens whiel trying to write  > 5 MB files.
> and I always disable the antivirus before doing any performance test
> on the machines.
>
> Thanks & Regards

The code is as follows

FILE * fp = fopen(fileName, "wb");
// a for loop for writing data into fp;
fclose(fp);
.......
// in another function immediately after the above one
CreateFile (fileName,
GENERIC_READ,
FILE_SHARE_READ,
NULL,
createDist,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN ,
NULL );

On some machine the fclose is slow and on some the CreateFile. I guess
the calls are slow because the process is waiting for the IO to
complet.
I put a log message just after fclose() and as soon as the message
appeared in the log I tried kiling my application from task manager.
But it did not get killed immediately though I kept trying again an
again. It took around 15 seconds before it got killed and disappeared
from Taskmanager.
I guess the OS was flushing the buffers to the disk and hence was not
allowing the task to get killed, as soon as the bufferes were flushed
the task got killed.

But why does the flushing behavior differs significantly across
systems when the CRT is statically linked.

I will check those harddrive driver and other configurations also.

Thanks & Regards

From: Cholo Lennon on 19 Feb 2010 08:08
Rahul wrote:
> On Feb 19, 10:25 am, "Tom Serface" <tserf...(a)msn.com> wrote:
>> If you are doing the same test with fopen vs. CreateFile on the same machine
>> under the same conditions I would expect CreateFile to be faster if anything
>> at all. It might be in the way you are opening CreateFile. Maybe you could
>> list the code where you do the call to open the file...
>>
>> Tom
>>
>> "Rahul" <rsharma.ch...(a)gmail.com> wrote in message
>>
>> news:71165977-5bb4-4e8f-a3cc-631b969941d4(a)k5g2000pra.googlegroups.com...
>> On Feb 18, 5:51 pm, "Francois PIETTE" <fpie...(a)newsgroups.nospam>
>> wrote:
>>
>>
>>
>>
>>
>>>> My application writes data in a file using fopen/fwrite/fclose and
>>>> immediately after fclose I try to open the same file using. the
>>>> windows CreateFile() function.
>>>> In one of my machine all are very fast and the total process finishes
>>>> in < 4 seconds.
>>>> But on one machine fclose itself takes around 15 seconds, I tried
>>>> using setbuf(fp, NULL) and calling fflush(fp) after every write, but
>>>> then also fclose took 15 seconds. I also tried using the low level
>>>> functions _open, _close etc. but there also the _close took 15 second
>>>> of time.
>>>> What is more strange to me is that there is one more machine on which
>>>> fopen/fwrite/fclose works quite fast but the last CreateFile() call
>>>> takes > 15 seconds to open the same file.
>>> Look for so called "security product". For example an antivirus program
>>> may
>>> be buggy and tak a lot of time processing the data.
>>> Also have a look at disk fragmentation and bad sectors.
>>> On the computer experiencing slow response, does other software suffer
>>> from
>>> the same problem or is this specific to one application ?
>>> --
>>> francois.pie...(a)overbyte.be
>>> The author of the freeware multi-tier middleware MidWare
>>> The author of the freeware Internet Component Suite
>>> (ICS)http://www.overbyte.be
>> Hi Francois,
>>
>> I do not know about other softwares, but the disk is highly
>> fragmented. however for small files the fclose/ CreateFile works
>> pretty fast. the problem happens whiel trying to write > 5 MB files.
>> and I always disable the antivirus before doing any performance test
>> on the machines.
>>
>> Thanks & Regards
>
> The code is as follows
>
> FILE * fp = fopen(fileName, "wb");
> // a for loop for writing data into fp;
> fclose(fp);
> ......
> // in another function immediately after the above one
> CreateFile (fileName,
> GENERIC_READ,
> FILE_SHARE_READ,
> NULL,
> createDist,
> FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN ,
> NULL );
>
> On some machine the fclose is slow and on some the CreateFile. I guess
> the calls are slow because the process is waiting for the IO to
> complet.
> I put a log message just after fclose() and as soon as the message
> appeared in the log I tried kiling my application from task manager.
> But it did not get killed immediately though I kept trying again an
> again. It took around 15 seconds before it got killed and disappeared
> from Taskmanager.
> I guess the OS was flushing the buffers to the disk and hence was not
> allowing the task to get killed, as soon as the bufferes were flushed
> the task got killed.
>
> But why does the flushing behavior differs significantly across
> systems when the CRT is statically linked.
>
> I will check those harddrive driver and other configurations also.

As M said, check hardware configuration, especially if you have an IDE
drive. It's possible that you have a drive with DMA disabled (go to
Control Panel/System/Device Manager/IDE controllers)

>
> Thanks & Regards
>


Regards

--
Cholo Lennon
Bs.As.
ARG
From: Francois PIETTE on 20 Feb 2010 04:22
>> Look for so called "security product". For example an antivirus program
>> may
>> be buggy and tak a lot of time processing the data.
>> Also have a look at disk fragmentation and bad sectors.

> I do not know about other softwares, but the disk is highly
> fragmented.

Defragment the disk is then mandatory.
Having a too much fragmented disk not only result in poor performance but
may result in a disk which can't no more be defragmented with defrag tool
and require a full backup/formet/rerstore cycle.

> On the computer experiencing slow response, does other software suffer
> from
> the same problem or is this specific to one application ?

You have not answered this one.

--
francois.piette(a)overbyte.be
The author of the freeware multi-tier middleware MidWare
The author of the freeware Internet Component Suite (ICS)
http://www.overbyte.be

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