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authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:34:16 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:34:16 +0300
commit7d62159919c90fbcd9ee808e9f1b776eae990d53 (patch)
treea5deb873ea9db3e055e4e7c577ab1326b651737c /mm
parent43686598b55785bfc1f961b3731b2302fe08f393 (diff)
parent32c97d980e2eef25465d453f2956a9ca68926a3c (diff)
downloadlinux-7d62159919c90fbcd9ee808e9f1b776eae990d53.tar.xz
Merge tag 'hyperv-next-signed-20221208' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu: - Drop unregister syscore from hyperv_cleanup to avoid hang (Gaurav Kohli) - Clean up panic path for Hyper-V framebuffer (Guilherme G. Piccoli) - Allow IRQ remapping to work without x2apic (Nuno Das Neves) - Fix comments (Olaf Hering) - Expand hv_vp_assist_page definition (Saurabh Sengar) - Improvement to page reporting (Shradha Gupta) - Make sure TSC clocksource works when Linux runs as the root partition (Stanislav Kinsburskiy) * tag 'hyperv-next-signed-20221208' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Remove unregister syscore call from Hyper-V cleanup iommu/hyper-v: Allow hyperv irq remapping without x2apic clocksource: hyper-v: Add TSC page support for root partition clocksource: hyper-v: Use TSC PFN getter to map vvar page clocksource: hyper-v: Introduce TSC PFN getter clocksource: hyper-v: Introduce a pointer to TSC page x86/hyperv: Expand definition of struct hv_vp_assist_page PCI: hv: update comment in x86 specific hv_arch_irq_unmask hv: fix comment typo in vmbus_channel/low_latency drivers: hv, hyperv_fb: Untangle and refactor Hyper-V panic notifiers video: hyperv_fb: Avoid taking busy spinlock on panic path hv_balloon: Add support for configurable order free page reporting mm/page_reporting: Add checks for page_reporting_order param
Diffstat (limited to 'mm')
-rw-r--r--mm/page_reporting.c50
1 files changed, 45 insertions, 5 deletions
diff --git a/mm/page_reporting.c b/mm/page_reporting.c
index 382958eef8a9..79a8554f024c 100644
--- a/mm/page_reporting.c
+++ b/mm/page_reporting.c
@@ -11,10 +11,42 @@
#include "page_reporting.h"
#include "internal.h"
-unsigned int page_reporting_order = MAX_ORDER;
-module_param(page_reporting_order, uint, 0644);
+/* Initialize to an unsupported value */
+unsigned int page_reporting_order = -1;
+
+static int page_order_update_notify(const char *val, const struct kernel_param *kp)
+{
+ /*
+ * If param is set beyond this limit, order is set to default
+ * pageblock_order value
+ */
+ return param_set_uint_minmax(val, kp, 0, MAX_ORDER-1);
+}
+
+static const struct kernel_param_ops page_reporting_param_ops = {
+ .set = &page_order_update_notify,
+ /*
+ * For the get op, use param_get_int instead of param_get_uint.
+ * This is to make sure that when unset the initialized value of
+ * -1 is shown correctly
+ */
+ .get = &param_get_int,
+};
+
+module_param_cb(page_reporting_order, &page_reporting_param_ops,
+ &page_reporting_order, 0644);
MODULE_PARM_DESC(page_reporting_order, "Set page reporting order");
+/*
+ * This symbol is also a kernel parameter. Export the page_reporting_order
+ * symbol so that other drivers can access it to control order values without
+ * having to introduce another configurable parameter. Only one driver can
+ * register with the page_reporting driver for the service, so we have just
+ * one control parameter for the use case(which can be accessed in both
+ * drivers)
+ */
+EXPORT_SYMBOL_GPL(page_reporting_order);
+
#define PAGE_REPORTING_DELAY (2 * HZ)
static struct page_reporting_dev_info __rcu *pr_dev_info __read_mostly;
@@ -330,10 +362,18 @@ int page_reporting_register(struct page_reporting_dev_info *prdev)
}
/*
- * Update the page reporting order if it's specified by driver.
- * Otherwise, it falls back to @pageblock_order.
+ * If the page_reporting_order value is not set, we check if
+ * an order is provided from the driver that is performing the
+ * registration. If that is not provided either, we default to
+ * pageblock_order.
*/
- page_reporting_order = prdev->order ? : pageblock_order;
+
+ if (page_reporting_order == -1) {
+ if (prdev->order > 0 && prdev->order <= MAX_ORDER)
+ page_reporting_order = prdev->order;
+ else
+ page_reporting_order = pageblock_order;
+ }
/* initialize state and work structures */
atomic_set(&prdev->state, PAGE_REPORTING_IDLE);