[PATCH v2 4/5] mm: memory_hotplug: Add memory hotremove probe device
From: Andrea Reale <hidden>
Date: 2017-11-23 11:15:02
Also in:
linux-mm, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, memory hot(un)plug, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, David Hildenbrand, Oscar Salvador, Linus Torvalds
Adding a "remove" sysfs handle that can be used to trigger memory hotremove manually, exactly simmetrically with what happens with the "probe" device for hot-add. This is usueful for architecture that do not rely on ACPI for memory hot-remove. Signed-off-by: Andrea Reale <redacted> Signed-off-by: Maciej Bielski <redacted> --- drivers/base/memory.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 1d60b58..8ccb67c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c@@ -530,7 +530,36 @@ memory_probe_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store); -#endif + +#ifdef CONFIG_MEMORY_HOTREMOVE +static ssize_t +memory_remove_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + u64 phys_addr; + int nid, ret; + unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block; + + ret = kstrtoull(buf, 0, &phys_addr); + if (ret) + return ret; + + if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1)) + return -EINVAL; + + nid = memory_add_physaddr_to_nid(phys_addr); + ret = lock_device_hotplug_sysfs(); + if (ret) + return ret; + + remove_memory(nid, phys_addr, + MIN_MEMORY_BLOCK_SIZE * sections_per_block); + unlock_device_hotplug(); + return count; +} +static DEVICE_ATTR(remove, S_IWUSR, NULL, memory_remove_store); +#endif /* CONFIG_MEMORY_HOTREMOVE */ +#endif /* CONFIG_ARCH_MEMORY_PROBE */ #ifdef CONFIG_MEMORY_FAILURE /*
@@ -790,6 +819,9 @@ bool is_memblock_offlined(struct memory_block *mem) static struct attribute *memory_root_attrs[] = { #ifdef CONFIG_ARCH_MEMORY_PROBE &dev_attr_probe.attr, +#ifdef CONFIG_MEMORY_HOTREMOVE + &dev_attr_remove.attr, +#endif #endif #ifdef CONFIG_MEMORY_FAILURE
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2.7.4