From: Zach Brown <zab@redhat.com>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: Lin Feng <linfeng@cn.fujitsu.com>,
akpm@linux-foundation.org, mgorman@suse.de, bcrl@kvack.org,
viro@zeniv.linux.org.uk, khlebnikov@openvz.org,
walken@google.com, kamezawa.hiroyu@jp.fujitsu.com,
minchan@kernel.org, riel@redhat.com, rientjes@google.com,
isimatu.yasuaki@jp.fujitsu.com, wency@cn.fujitsu.com,
laijs@cn.fujitsu.com, jiang.liu@huawei.com, linux-mm@kvack.org,
linux-aio@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] fs/aio.c: use get_user_pages_non_movable() to pin ring pages when support memory hotremove
Date: Mon, 4 Feb 2013 15:02:09 -0800 [thread overview]
Message-ID: <20130204230209.GK14246@lenny.home.zabbo.net> (raw)
In-Reply-To: <x49ehgw85w4.fsf@segfault.boston.devel.redhat.com>
> > index 71f613c..0e9b30a 100644
> > --- a/fs/aio.c
> > +++ b/fs/aio.c
> > @@ -138,9 +138,15 @@ static int aio_setup_ring(struct kioctx *ctx)
> > }
> >
> > dprintk("mmap address: 0x%08lx\n", info->mmap_base);
> > +#ifdef CONFIG_MEMORY_HOTREMOVE
> > + info->nr_pages = get_user_pages_non_movable(current, ctx->mm,
> > + info->mmap_base, nr_pages,
> > + 1, 0, info->ring_pages, NULL);
> > +#else
> > info->nr_pages = get_user_pages(current, ctx->mm,
> > info->mmap_base, nr_pages,
> > 1, 0, info->ring_pages, NULL);
> > +#endif
>
> Can't you hide this in your 1/1 patch, by providing this function as
> just a static inline wrapper around get_user_pages when
> CONFIG_MEMORY_HOTREMOVE is not enabled?
Yes, please. Having callers duplicate the call site for a single
optional boolean input is unacceptable.
But do we want another input argument as a name? Should aio have been
using get_user_pages_fast()? (and so now _fast_non_movable?)
I wonder if it's time to offer the booleans as a _flags() variant, much
like the current internal flags for __get_user_pages(). The write and
force arguments are already booleans, we have a different fast api, and
now we're adding non-movable. The NON_MOVABLE flag would be 0 without
MEMORY_HOTREMOVE, easy peasy.
Turning current callers' mysterious '1, 1' in to 'WRITE|FORCE' might
also be nice :).
No?
- z
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next prev parent reply other threads:[~2013-02-04 23:02 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-04 10:04 [PATCH 0/2] mm: hotplug: implement non-movable version of get_user_pages() to kill long-time pin pages Lin Feng
2013-02-04 10:04 ` [PATCH 1/2] mm: hotplug: implement non-movable version of get_user_pages() called get_user_pages_non_movable() Lin Feng
2013-02-05 0:06 ` Andrew Morton
2013-02-05 0:18 ` Andrew Morton
2013-02-05 3:09 ` Lin Feng
2013-02-05 21:13 ` Andrew Morton
2013-02-05 11:57 ` Mel Gorman
2013-02-05 13:32 ` Mel Gorman
2013-02-19 13:37 ` Lin Feng
2013-02-20 2:34 ` Lin Feng
2013-02-20 2:44 ` Wanpeng Li
2013-02-20 2:59 ` Lin Feng
2013-02-20 2:44 ` Wanpeng Li
2013-02-20 2:44 ` Wanpeng Li
2013-02-20 9:58 ` Simon Jeons
2013-02-20 10:23 ` Lin Feng
2013-02-20 11:31 ` Simon Jeons
2013-02-20 11:54 ` Lin Feng
2013-02-06 2:26 ` Michel Lespinasse
2013-02-06 10:41 ` Mel Gorman
2013-02-18 10:34 ` Lin Feng
2013-02-18 15:17 ` Mel Gorman
2013-02-19 9:55 ` Lin Feng
2013-02-19 10:34 ` Mel Gorman
2013-02-04 10:04 ` [PATCH 2/2] fs/aio.c: use get_user_pages_non_movable() to pin ring pages when support memory hotremove Lin Feng
2013-02-04 15:18 ` Jeff Moyer
2013-02-04 23:02 ` Zach Brown [this message]
2013-02-05 5:35 ` Lin Feng
2013-02-05 5:06 ` Lin Feng
2013-02-05 0:58 ` [PATCH 0/2] mm: hotplug: implement non-movable version of get_user_pages() to kill long-time pin pages Minchan Kim
2013-02-05 4:42 ` Lin Feng
2013-02-05 5:25 ` Minchan Kim
2013-02-05 6:18 ` Lin Feng
2013-02-05 7:45 ` Minchan Kim
2013-02-05 8:27 ` Lin Feng
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