From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [patch 4/9] mm: lockless pagecache lookups From: Lee Schermerhorn In-Reply-To: <20060922172120.22370.4933.sendpatchset@linux.site> References: <20060922172042.22370.62513.sendpatchset@linux.site> <20060922172120.22370.4933.sendpatchset@linux.site> Content-Type: text/plain Date: Fri, 22 Sep 2006 16:01:11 -0400 Message-Id: <1158955271.5584.58.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andrew Morton , Linux Memory Management List-ID: On Fri, 2006-09-22 at 21:22 +0200, Nick Piggin wrote: > Combine page_cache_get_speculative with lockless radix tree lookups to > introduce lockless page cache lookups (ie. no mapping->tree_lock on > the read-side). > > The only atomicity changes this introduces is that the gang pagecache > lookup functions now behave as if they are implemented with multiple > find_get_page calls, rather than operating on a snapshot of the pages. > In practice, this atomicity guarantee is not used anyway, and it is > difficult to see how it could be. Gang pagecache lookups are designed > to replace individual lookups, so these semantics are natural. > vvv - stale comment? > Swapcache can no longer use find_get_page, because it has a different > method of encoding swapcache position into the page. Introduce a new > find_get_swap_page for it. ^^^ > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org