Subject: Re: genfs_putpages with PGO_SYNCIO
To: YAMAMOTO Takashi <>
From: enami tsugutomo <>
List: tech-kern
Date: 01/21/2003 11:15:22
YAMAMOTO Takashi <> writes:

> hi.
> > > > sure.  I agree that struct buf here is overkill.
> > > > maybe we should have stripped version of struct buf.
> > > 
> > > i made a new patch, with a new struct (stripped version of buf).
> > > how about this?
> > 
> > Hm, what is the benefit of using stripped version of struct buf?  At
> code sharing with biowait/biodone.
> > least you're forced to use slight hack to prevent `done' routine being
> > called by borrowing struct buf related routine for this.  Is so much
> > code duplicated without this?
> not so much, i think.
> do you mean "it's better to introduce a completely different structure
> than abusing a part of struct buf" ?

Yes.  IMHO, they (new one vs. struct buf and bio* routine) describe
different thing (the former is just related to GOP_PUTPAGES and
GOP_WRITE).  E.g., if one might want to limit the number of async
write issued at a time, the code will wait in the middle of loop in
_putpages routine.  For this, not using struct buf will be cleaner.

> > if (async) {...} just above this change isn't necessary anymore.
> sure. i preserved it just for UVMHIST_LOG.

Since code path is same now, the logged `flags' value is enough.

BTW, is this change results noticable effect?