From: Zach Brown <zach.brown@oracle.com>
To: Andrew Morton <akpm@osdl.org>
Cc: Chris Mason <chris.mason@oracle.com>, linux-fsdevel@vger.kernel.org
Subject: Re: [RFC PATCH 0/2] O_DIRECT locking rework
Date: Fri, 20 Oct 2006 13:03:24 -0700 [thread overview]
Message-ID: <45392B8C.3070208@oracle.com> (raw)
In-Reply-To: <20061020123058.8b422339.akpm@osdl.org>
> I think the fake placeholder page can be a kernel-wide thing rather than
> per-dio? That would be most desirable because then we have
>
> #define PagePlaceHolder(page) (page == global_placeholder_page)
That would be nice. The current patch hashes the page pointer with
page_waitqueue(page) to get at the zone's hashed wait queue buckets. It
would probably want to avoid that hot spot by getting at the buckets by
hashing the mapping and file offset, I guess.
Chris and I have also talked about using tags in the nodes to mark slots
that only lead to place holder leaves instead of actually populating the
leaves with these place holder pages. We'd avoid having to populate the
tree for larger IOs, and callers wouldn't have to filter out the place
holders from lookups, but the tree nodes would grow for a rare user :/.
- z
next prev parent reply other threads:[~2006-10-20 20:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-10-20 18:32 [RFC PATCH 0/2] O_DIRECT locking rework Chris Mason
2006-10-20 18:38 ` [RFC PATCH 1/2] placeholder pages Chris Mason
2006-10-20 18:41 ` [RFC PATCH 1/2] page cache locking for O_DIRECT Chris Mason
2006-10-20 19:30 ` [RFC PATCH 0/2] O_DIRECT locking rework Andrew Morton
2006-10-20 20:03 ` Zach Brown [this message]
2006-10-20 20:12 ` Chris Mason
2006-10-20 20:05 ` Chris Mason
2006-10-20 20:23 ` Andi Kleen
2006-10-24 19:34 ` Chris Mason
2006-10-24 19:38 ` [RFC PATCH 1/2] placeholder pages Chris Mason
2006-10-24 19:40 ` [RFC PATCH 2/2] O_DIRECT locking via placeholders Chris Mason
2006-10-24 20:28 ` [RFC PATCH 0/2] O_DIRECT locking rework Badari Pulavarty
2006-10-24 20:50 ` Chris Mason
2006-10-24 21:52 ` Badari Pulavarty
2006-10-24 22:22 ` Chris Mason
2006-10-24 22:47 ` Badari Pulavarty
2006-10-24 22:37 ` Russell Cattelan
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