From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Holt Date: Wed, 06 Feb 2008 10:44:39 +0000 Subject: Re: [patch] Fix large MCA bootmem allocation Message-Id: <20080206104438.GE3875@sgi.com> List-Id: References: <20080205193232.GA8834@sgi.com> In-Reply-To: <20080205193232.GA8834@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org On Wed, Feb 06, 2008 at 12:50:11PM +0900, Hidetoshi Seto wrote: > Hidetoshi Seto wrote: >> Then, I suppose we need a CPU_UP_PREPARE callback to allocate memory >> before hot-added CPU enters cpu_init(). > > Ah, we cannot allocate bootmem later, so it would be better to make > the callback to return NOTIFY_BAD if (!__per_cpu_mca[hcpu]). > bootmem is only used for the first cpu. The other cpus use regular allocations. So we should be able to do a CPU_UP_PREPARE. Comparing the severity of allocating a ton of extra memory with the chance that we fail on an allocation and given that there are likely other things in the cpu_init path which are not checked, do you see the lack of check as a show-stopper for this patch or would you accept this patch with the plan being fixup the cpu_init path later? Thanks, Robin