From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave@linux.vnet.ibm.com (Dave Hansen) Date: Thu, 31 Mar 2011 15:26:51 -0700 Subject: [PATCH 04/12] mm: alloc_contig_freed_pages() added In-Reply-To: References: <1301577368-16095-1-git-send-email-m.szyprowski@samsung.com> <1301577368-16095-5-git-send-email-m.szyprowski@samsung.com> <1301587083.31087.1032.camel@nimitz> <1301606078.31087.1275.camel@nimitz> Message-ID: <1301610411.30870.29.camel@nimitz> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 2011-04-01 at 00:18 +0200, Michal Nazarewicz wrote: > On Thu, 31 Mar 2011 23:14:38 +0200, Dave Hansen wrote: > > We BUG_ON() in bootmem. Basically if we try to allocate an early-boot > > structure and fail, we're screwed. We can't keep running without an > > inode hash, or a mem_map[]. > > > > This looks like it's going to at least get partially used in drivers, at > > least from the examples. Are these kinds of things that, if the driver > > fails to load, that the system is useless and hosed? Or, is it > > something where we might limp along to figure out what went wrong before > > we reboot? > > Bug in the above place does not mean that we could not allocate memory. It > means caller is broken. Could you explain that a bit? Is this a case where a device is mapped to a very *specific* range of physical memory and no where else? What are the reasons for not marking it off limits at boot? I also saw some bits of isolation and migration in those patches. Can't the migration fail? -- Dave