About QUOTA support in stock kernel (resent)

[Patrick Dung]

I am curious if other operating systems have this performance impact.

Could we have some workaround or need some code improvement?
For example:
Do the checking/accounting only if the specific mount point has enabled quota.
etc..

Regards,
Patrick

--- On Tue, 12/25/12, Konstantin Belousov <kostikbel at gmail.com> wrote:

From: Konstantin Belousov <kostikbel at gmail.com>
Subject: Re: About QUOTA support in stock kernel (resent)
To: "Eitan Adler" <lists at eitanadler.com>
Cc: "Patrick Dung" <patrick_dkt at yahoo.com.hk>, "freebsd hackers" <freebsd-hackers at freebsd.org>, fs at freebsd.org
Date: Tuesday, December 25, 2012, 11:29 PM

On Tue, Dec 25, 2012 at 10:23:26AM -0500, Eitan Adler wrote:
> On 25 December 2012 10:07, Konstantin Belousov <kostikbel at gmail.com> wrote:
> > Enabling quota by default would cause small overhead, like one mutex acquire,
> > for each inode and block alloc/dealloc, even for mount without quotas enabled.
> 
> Why is this, and can it be avoided (for mounts without quotas)?
Because system should check whether quota is enabled to do the accounting.

> 
> > Might be, it is reasonable to just enable it now. Unless somebody provide
> > valid objections and I do not forget, I will do it in a week for HEAD.
> 
> 
> 
> -- 
> Eitan Adler