From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mel Gorman Message-Id: <20080422183133.13750.57133.sendpatchset@skynet.skynet.ie> Subject: [PATCH 0/4] Verification and debugging of memory initialisation V3 Date: Tue, 22 Apr 2008 19:31:33 +0100 (IST) Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: Mel Gorman , mingo@elte.hu, linux-kernel@vger.kernel.org, clameter@sgi.com List-ID: Other than a rebase to the latest -mm, there are not many big changes. Credit goes to Christoph Lameter, an off-list reviewer and in particular Ingo Molnar for helping bash this into shape. Changelog since V2 o (Mel) Rebase to 2.6.25-mm1 and rewrite zonelist dump o (Mel) Depend on DEBUG_VM instead of DEBUG_KERNEL o (Mel) Use __meminitdata instead of __initdata for logging level o (Christoph) Get rid of FLAGS_RESERVED references o (Christoph) Print out flag usage information o (Ingo) Default do the verifications on DEBUG_VM and instead control the level of verbose logging with mminit_loglevel= instead of mminit_debug_level= o (Anon) Log at KERN_DEBUG level o (Anon) Optimisation to the mminit_debug_printk macro Changelog since V1 o (Ingo) Make memory initialisation verification a DEBUG option depending on DEBUG_KERNEL option. By default it will then to verify structures but tracing can be enabled via the command-line. Without the CONFIG option, checks will still be made on PFN ranges passed by the architecture-specific code and a warning printed once if a problem is encountered o (Ingo) WARN_ON_ONCE when PFNs from the architecture violate SPARSEMEM limitations. The warning should be "harmless" as the system will boot regardless but it acts as a reminder that bad input is being used. o (Anon) Convert mminit_debug_printk() to a macro o (Anon) Spelling mistake corrections o (Anon) Use of KERN_CONT properly for multiple printks o (Mel) Reshuffle the patches so that the zonelist printing is at the end of the patchset. This is because -mm requires a different patch to print zonelists and this allows the end patch to be temporarily dropped when testing against -mm o (Mel) Rebase on top of Ingo's sparsemem fix for easier testing o (Mel) Document mminit_debug_level= o (Mel) Fix check on pageflags where the masks were not being shifted o (Mel) The zone ID should should have used page_zonenum not page_zone_id o (Mel) Iterate all zonelists correctly o (Mel) Correct typo of SECTIONS_SHIFT Boot initialisation has always been a bit of a mess with a number of ugly points. While significant amounts of the initialisation is architecture-independent, it trusts of the data received from the architecture layer. This was a mistake in retrospect as it has resulted in a number of difficult-to-diagnose bugs. This patchset adds some validation and tracing to memory initialisation when CONFIG_DEBUG_VM is set. The configuration option can be explicitly disabled for embedded systems. It also introduces a few basic defencive measures and depending on a boot parameter, will perform additional tests for errors "that should never occur". The intention is that additional checks are added over time that would have identified mysterious boot failures faster. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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