Re: [PATCH] Add block device speciffic splice write method

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, 23 Oct 2008 08:51:13 +0200 Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:

> On Wed, Oct 22 2008, Andrew Morton wrote:
> > On Thu, 23 Oct 2008 08:29:23 +0200 Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
> > 
> > > > But really it'd be better if the throttling happened down in
> > > > pipe_to_file(), on a per-page basis.  As it stands we can dirty an
> > > > arbitrary number of pagecache pages without throttling.  I think?
> > > 
> > > That's pretty exactly why it isn't done in the actor, to avoid doing it
> > > per-page. As it's going to be PIPE_BUFFERS (16) pages max, I think this
> > > is better.
> > > 
> > > Back in the splice early days, the balance_dirty_pages() actually showed
> > > up in profiles when it was done on a per-page basis. So I'm reluctant to
> > > change it :-)
> > 
> > That's why (the misnamed) balance_dirty_pages_ratelimited() exists?
> 
> I think that is what was used, but the details are a little hazy at this
> point. So I can't say for sure.

All that function does is to bump a per-cpu variable and
once-per-thousand or so it does the balance.  If it was causing
problems in the splice application we want to know, because write()
uses it!

>  In this case it's moot anyway, since we can kill it.

Nope, we can only remove it if the fd is O_SYNC||is_sync().
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux