Hello Stefan, On Thu, Dec 01, 2011 at 05:10:23PM +0100, Stefan Hellermann wrote: > Am 01.12.2011 16:39, schrieb Uwe Kleine-König: > > The problem is that the memory for mem_map is allocated using: > > > > map = alloc_bootmem_node_nopanic(pgdat, size); > > > > without any error checking. The _nopanic was introduced by commit > > > > 8f389a99 (mm: use alloc_bootmem_node_nopanic() on really needed path) > > > > I don't understand the commit's log and don't really see why it should > > be allowed to not panic if the allocation failes here but use a NULL > > pointer instead. > > I put the people involved in 8f389a99 on Cc, maybe someone can comment? > > > > Apart from that it seems I cannot use flatmem as is on my machine. It > > has only 128kiB@0x10000000 + 1MiB@0x80000000 and needs 14MiB to hold the > > table of "struct page"s. :-( > > > > Best regards > > Uwe > > > The commit was made after an bug report from me. I have an old x86 > tablet pc with only 8Mb Ram. This machine fails early on bootup without > this commit. I found an archived message of the bug report here: > http://comments.gmane.org/gmane.linux.kernel/1135909 I saw that, too, but still I think that at least the last hunk in this patch is wrong. (I didn't check the others.) For me the allocation for mem_map failed and instead of handling the error somehow (be it a panic or not) just using NULL isn't nice. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>