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From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>, Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>,
	Matthew Wilcox <willy@infradead.org>,
	linux-mm@kvack.org, LKML <linux-kernel@vger.kernel.org>,
	Thomas Garnier <thgarnie@google.com>,
	Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Joel Fernandes <joelaf@google.com>,
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	Tejun Heo <tj@kernel.org>,
	"Uladzislau Rezki (Sony)" <urezki@gmail.com>
Subject: [PATCH v4 3/3] mm/vmap: add DEBUG_AUGMENT_LOWEST_MATCH_CHECK macro
Date: Sat,  6 Apr 2019 20:35:08 +0200
Message-ID: <20190406183508.25273-4-urezki@gmail.com> (raw)
In-Reply-To: <20190406183508.25273-1-urezki@gmail.com>

This macro adds some debug code to check that vmap allocations
are happened in ascending order.

By default this option is set to 0 and not active. It requires
recompilation of the kernel to activate it. Set to 1, compile
the kernel.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
---
 mm/vmalloc.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a74e605e042f..92b784d8088c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -325,6 +325,7 @@ EXPORT_SYMBOL(vmalloc_to_pfn);
 /*** Global kva allocator ***/
 
 #define DEBUG_AUGMENT_PROPAGATE_CHECK 0
+#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
 
 #define VM_LAZY_FREE	0x02
 #define VM_VM_AREA	0x04
@@ -833,6 +834,44 @@ find_vmap_lowest_match(unsigned long size,
 	return NULL;
 }
 
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+#include <linux/random.h>
+
+static struct vmap_area *
+find_vmap_lowest_linear_match(unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	struct vmap_area *va;
+
+	list_for_each_entry(va, &free_vmap_area_list, list) {
+		if (!is_within_this_va(va, size, align, vstart))
+			continue;
+
+		return va;
+	}
+
+	return NULL;
+}
+
+static void
+find_vmap_lowest_match_check(unsigned long size)
+{
+	struct vmap_area *va_1, *va_2;
+	unsigned long vstart;
+	unsigned int rnd;
+
+	get_random_bytes(&rnd, sizeof(rnd));
+	vstart = VMALLOC_START + rnd;
+
+	va_1 = find_vmap_lowest_match(size, 1, vstart);
+	va_2 = find_vmap_lowest_linear_match(size, 1, vstart);
+
+	if (va_1 != va_2)
+		pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
+			va_1, va_2, vstart);
+}
+#endif
+
 enum fit_type {
 	NOTHING_FIT = 0,
 	FL_FIT_TYPE = 1,	/* full fit */
@@ -975,6 +1014,10 @@ __alloc_vmap_area(unsigned long size, unsigned long align,
 	if (ret)
 		return vend;
 
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+	find_vmap_lowest_match_check(size);
+#endif
+
 	return nva_start_addr;
 }
 
-- 
2.11.0


      parent reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-06 18:35 [PATCH v4 0/3] improve vmap allocation Uladzislau Rezki (Sony)
2019-04-06 18:35 ` [PATCH v4 1/3] mm/vmap: keep track of free blocks for " Uladzislau Rezki (Sony)
2019-04-08 23:19   ` Roman Gushchin
2019-04-09  9:45     ` Uladzislau Rezki
2019-05-14 21:19   ` Andrew Morton
2019-05-15 15:24     ` Uladzislau Rezki
2019-05-16  7:30       ` Uladzislau Rezki
2019-04-06 18:35 ` [PATCH v4 2/3] mm/vmap: add DEBUG_AUGMENT_PROPAGATE_CHECK macro Uladzislau Rezki (Sony)
2019-04-06 18:35 ` Uladzislau Rezki (Sony) [this message]

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