RE: question: high virtual memory usage
Original Message From: Brian Dessent Sent: 14 June 2005 03:23 Procexp's virtual size column seems to be a meaningless number that procexp somehow arrives at. It's the amount of reserved-but-not-yert-committed memory. It's not just cygwin processes that it seems to come up with outragiously high values for. On my system there is a svchost.exe process (part of the operating system) that uses 10,192KB working set and 10,400KB private bytes, but process explorer lists its virtual size as 143,260KB. Clearly this process is not using anywhere near 143MB of RAM. I really think you should ignore this column, it does not say anything useful. If I add up the total sizes of all the values of this column on my system, I get something like 7GB, and I only have 1GB of ram and 512MB of swap. It tells you the total amount of memory space out of the processes entire virtual 2Gb address space that has been allocated; that is, the amount of the memory map that has been laid out, but not yet necessarily accessed or used; reserved pages require no significant overhead until they are actually used and (real or virtual-paged) memory has to be assigned to them. cheers, DaveK -- Can't think of a witty .sigline today -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Igor Pechtchanski wrote: Still cannot reproduce (my Process Explorer shows the same numbers as the TaskManager). Which version of Process Explorer are you using? I can. I've just downloaded v9.11 for Win2K/XP/NT 32-bit. Anyway, it shows these wildly inflated Virtual Sizes for a lot of applications (e.g. YPager's VM size is claimed to be 155MB (!), and Outlook's is 510MB (!!! though I wouldn't be shocked if this was the only one that showed such a figure :-)) -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
RE: question: high virtual memory usage
Original Message From: Shankar Unni Sent: 14 June 2005 18:10 Igor Pechtchanski wrote: Still cannot reproduce (my Process Explorer shows the same numbers as the TaskManager). Which version of Process Explorer are you using? I can. I've just downloaded v9.11 for Win2K/XP/NT 32-bit. Anyway, it shows these wildly inflated Virtual Sizes They're not wildly inflated. They are correct, it's just that you've (IIUIC) misinterpreted what the figures refer to. Please read the previous post in this thread for more information. In anycase, this is all getting off topic for the main cygwin list. Oh-oh, here come those chickens![*] bock-bock-bock-b'gaak! cheers, DaveK [*] http://cygwin.com/acronyms#TITTTL -- Can't think of a witty .sigline today -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
On Mon, 13 Jun 2005, Alexey Fayans wrote: All programs that use cygwin1.dll report very high virtual memory usage. For example, bash from standard package report usage of ~420MB. Is it how it should be? Hard to say without more information. Please see the Cygwin problem reporting guidelines at http://cygwin.com/problems.html. FWIW, I don't observe this on my machine (WinXP) -- all my bashes show around 2MB of virtual memory in the TaskManager. Igor P.S. Please make sure your mailer wraps long lines or sets Format=Flowed. -- http://cs.nyu.edu/~pechtcha/ |\ _,,,---,,_[EMAIL PROTECTED] ZZZzz /,`.-'`'-. ;-;;,_[EMAIL PROTECTED] |,4- ) )-,_. ,\ ( `'-' Igor Pechtchanski, Ph.D. '---''(_/--' `-'\_) fL a.k.a JaguaR-R-R-r-r-r-.-.-. Meow! The Sun will pass between the Earth and the Moon tonight for a total Lunar eclipse... -- WCBS Radio Newsbrief, Oct 27 2004, 12:01 pm EDT -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Igor Pechtchanski wrote: On Mon, 13 Jun 2005, Alexey Fayans wrote: All programs that use cygwin1.dll report very high virtual memory usage. For example, bash from standard package report usage of ~420MB. Is it how it should be? Hard to say without more information. Please see the Cygwin problem reporting guidelines at http://cygwin.com/problems.html. FWIW, I don't observe this on my machine (WinXP) -- all my bashes show around 2MB of virtual memory in the TaskManager. Igor P.S. Please make sure your mailer wraps long lines or sets Format=Flowed. If you're looking at memory usage from Process Explorer then it incorrectly displays such figures. -- I wake up every morning at nine and grab for the morning paper. Then I look at the obituary page. If my name is not on it, I get up. - Benjamin Franklin -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Alexey Fayans wrote: Look at screenshot: http://home.shad.pp.ru/tmp/cygwin.png You're using process explorer, not task manager, and process explorer does not interact well with Cygwin for whatever reason. In this case it seems the procexp is computing the VM size wrong. If you use task manager and look at the VM size column it will be correct. You'll have to take this up with sysinternals.com, it's not on topic for this list. The VM size column is not a good measure of the actual memory used. It does not correlate in any way to real memory, hence virtual. You should consider the working set column if you want to know how much memory a process is actually using. Brian -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Brian Dessent wrote: You're using process explorer, not task manager, and process explorer does not interact well with Cygwin for whatever reason. In this case it seems the procexp is computing the VM size wrong. If you use task manager and look at the VM size column it will be correct. You'll have to take this up with sysinternals.com, it's not on topic for this list. The VM size column is not a good measure of the actual memory used. It does not correlate in any way to real memory, hence virtual. You should consider the working set column if you want to know how much memory a process is actually using. Just to clarify: taskman's Mem usage column == procexp's Working set column and this is the amount of memory that is actually being used by the process. taskman's VM size column == procexp's Private bytes column and this is the total amount of code+data that has been assigned to the process, though not all of it is necessarily in use. procexp's virtual size is simply a representation of the amount of virutal memory that has been allocated to the process. Virtual memory is not real memory and it only means that X number of pages have been allocated, it says absolutely nothing about the actual memory used by the process, and you should ignore it completely unless you have a specific reason to need to know about it. Brian -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Brian Dessent wrote: Just to clarify: taskman's Mem usage column == procexp's Working set column and this is the amount of memory that is actually being used by the process. taskman's VM size column == procexp's Private bytes column and this is the total amount of code+data that has been assigned to the process, though not all of it is necessarily in use. procexp's virtual size is simply a representation of the amount of virutal memory that has been allocated to the process. Virtual memory is not real memory and it only means that X number of pages have been allocated, it says absolutely nothing about the actual memory used by the process, and you should ignore it completely unless you have a specific reason to need to know about it. That may be but it does represent the footprint of the process or at least the amount of memory + swap reserved (doesn't it?). As such I seek to minimize such usage. -- Why are people willing to get off their ass to search the entire room for the TV remote because they refuse to walk to the TV and change the channel manually? -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Igor Pechtchanski wrote: On Tue, 14 Jun 2005, Alexey Fayans wrote: All programs that use cygwin1.dll report very high virtual memory usage. For example, bash from standard package report usage of ~420MB. Is it how it should be? Hard to say without more information. Please see the Cygwin problem reporting guidelines at http://cygwin.com/problems.html. FWIW, I don't observe this on my machine (WinXP) -- all my bashes show around 2MB of virtual memory in the TaskManager. Look at screenshot: http://home.shad.pp.ru/tmp/cygwin.png Still cannot reproduce (my Process Explorer shows the same numbers as the TaskManager). Which version of Process Explorer are you using? It could also be a SysInternals bug, as Andrew suggested... I like Process Explorer. In fact I use it instead of Task Manager. But there are 2 things about Process Explorer that I don't like. One is this wrong reporting of virtual memory and the other is the fact that Process Explorer does not have a nice little graph of Network usage nor number of users logged in (in the case of XP for example). I sure wish that SysInternals would fix this but I'm not knowledgeable enough to confront them intelligently. -- 640K ought to be enough RAM for anybody. - Bill Gates, 1981 -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: question: high virtual memory usage
Andrew DeFaria wrote: That may be but it does represent the footprint of the process or at least the amount of memory + swap reserved (doesn't it?). As such I seek to minimize such usage. No, I don't think so. Taskman's VM size is what you are thinking of, and is what procexp calls private bytes. This is the total footprint of the process. The working set is the amount of that that is currently resident, i.e. available without a page fault. Procexp's virtual size column seems to be a meaningless number that procexp somehow arrives at. It's not just cygwin processes that it seems to come up with outragiously high values for. On my system there is a svchost.exe process (part of the operating system) that uses 10,192KB working set and 10,400KB private bytes, but process explorer lists its virtual size as 143,260KB. Clearly this process is not using anywhere near 143MB of RAM. I really think you should ignore this column, it does not say anything useful. If I add up the total sizes of all the values of this column on my system, I get something like 7GB, and I only have 1GB of ram and 512MB of swap. Brian -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
