Re: [5/5] pseries: Implement memory hotplug remove in the kernel
From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2014-09-17 07:07:30
On Mon, 2014-09-15 at 15:33 -0500, Nathan Fontenot wrote:
quoted hunk ↗ jump to hunk
This patch adds the ability to do memory hotplug remove in the kernel. Currently the hotplug add/remove of memory is handled by the drmgr command. The drmgr command performs the add/remove by performing some work in user-space and making requests to the kernel to handle other pieces. By moving all of the work to the kernel we can do the add and remove faster, and provide a common place to do memory hotplug for both the PowerVM and PowerKVM environments. Signed-off-by: Nathan Fontenot <redacted> --- arch/powerpc/platforms/pseries/hotplug-memory.c | 140 +++++++++++++++++++++++ 1 file changed, 139 insertions(+), 1 deletion(-)diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c index b254773..160c424 100644 --- a/arch/powerpc/platforms/pseries/hotplug-memory.c +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c@@ -193,7 +193,137 @@ static int pseries_remove_mem_node(struct device_node *np) pseries_remove_memblock(base, lmb_size); return 0; } + +static int lmb_is_removable(struct of_drconf_cell *lmb) +{
Do we not already have something like this?
+ int i, scns_per_block; + int rc = 1;
I can see this makes the &= work below. But what if block_sz / MIN_MEMORY_BLOCK_SIZE = 0 ?
+ unsigned long pfn, block_sz;
+ u64 phys_addr;
+
+ phys_addr = be64_to_cpu(lmb->base_addr);
+ block_sz = memory_block_size_bytes();
+ scns_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
+
+ for (i = 0; i < scns_per_block; i++) {
+ pfn = PFN_DOWN(phys_addr);
+ if (!pfn_present(pfn))
+ continue;
+
+ rc &= is_mem_section_removable(pfn, PAGES_PER_SECTION);
+ phys_addr += MIN_MEMORY_BLOCK_SIZE;
+ }
+
+ return rc;
+}+static int dlpar_memory_remove(struct pseries_hp_errorlog *hp_elog)
+{...
+}
Most of the same comments as for add. cheers