Date: Sun, 09 Dec 2001 21:07:14 -0500 From: Bill Moran <wmoran@potentialtech.com> To: Anthony Atkielski <anthony@freebie.atkielski.com> Cc: FreeBSD Questions <freebsd-questions@FreeBSD.ORG> Subject: Re: Diminishing free memory in top Message-ID: <3C1418D2.4010209@potentialtech.com> References: <00ac01c1811a$cb534790$0a00000a@atkielski.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Anthony Atkielski wrote: > I note when running top that the "Free" memory figure gradually diminishes > over time on the system, even (and perhaps especially) when the system is > idle. Am I correct in assuming that this means that many pages are not > necessarily active but still contain potentially useful information and thus > have not been freed by FreeBSD because the memory is not yet needed for > anything else? This seems to be what I understand from the descriptions of > FreeBSD memory management in the handbook, and it is supported by the fact > that the free figure jumps to something much larger if I run a program that > abruptly requests a lot of memory. Sounds like you've got a good grip on what's occurring. Notice the memory in the "inactive" category. This is the memory that still has potentially useful data in it. The overhead involved in converting inactive memroy to free memory is extremely low, therefore, the system keeps the inactive memory around a long as possible. If a process is restarted that exists in the inactive memory pool, it can start very quickly because most or all of its data is already in memory, and the system just converts the inactive pages to active pages. -- Bill Moran Potential Technology http://www.potentialtech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?3C1418D2.4010209>