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authorDavid S. Miller <davem@davemloft.net>2016-11-18 11:33:26 -0800
committerDavid S. Miller <davem@davemloft.net>2016-11-18 11:33:26 -0800
commit79c3dcbabb8fc9df45e283e288938a45ef1a7a16 (patch)
tree737814fa3368ed63e4cdb121d1ac2986bb54f4cd
parentsunbmac: Fix compiler warning (diff)
parentlockdep: Limit static allocations if PROVE_LOCKING_SMALL is defined (diff)
downloadlinux-dev-79c3dcbabb8fc9df45e283e288938a45ef1a7a16.tar.xz
linux-dev-79c3dcbabb8fc9df45e283e288938a45ef1a7a16.zip
Merge branch 'sparc-lockdep-small'
Babu Moger says: ==================== Adjust lockdep static allocations for sparc These patches limit the static allocations for lockdep data structures used for debugging locking correctness. For sparc, all the kernel's code, data, and bss, must have locked translations in the TLB so that we don't get TLB misses on kernel code and data. Current sparc chips have 8 TLB entries available that may be locked down, and with a 4mb page size, this gives a maximum of 32MB. With PROVE_LOCKING we could go over this limit and cause system boot-up problems. These patches limit the static allocations so that everything fits in current required size limit. patch 1 : Adds new config parameter CONFIG_PROVE_LOCKING_SMALL Patch 2 : Adjusts the sizes based on the new config parameter v2-> v3: Some more comments from Sam Ravnborg and Peter Zijlstra. Defined PROVE_LOCKING_SMALL as invisible and moved the selection to arch/sparc/Kconfig. v1-> v2: As suggested by Peter Zijlstra, keeping the default as is. Introduced new config variable CONFIG_PROVE_LOCKING_SMALL to handle sparc specific case. v0: Initial revision. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--arch/sparc/Kconfig1
-rw-r--r--kernel/locking/lockdep_internals.h20
-rw-r--r--lib/Kconfig.debug3
3 files changed, 21 insertions, 3 deletions
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 60145c9b9f84..165ecdd24d22 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -43,6 +43,7 @@ config SPARC
select ARCH_HAS_SG_CHAIN
select CPU_NO_EFFICIENT_FFS
select HAVE_ARCH_HARDENED_USERCOPY
+ select PROVE_LOCKING_SMALL if PROVE_LOCKING
config SPARC32
def_bool !64BIT
diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index 51c4b24b6328..c2b88490d857 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -46,6 +46,14 @@ enum {
(LOCKF_USED_IN_HARDIRQ_READ | LOCKF_USED_IN_SOFTIRQ_READ)
/*
+ * CONFIG_PROVE_LOCKING_SMALL is defined for sparc. Sparc requires .text,
+ * .data and .bss to fit in required 32MB limit for the kernel. With
+ * PROVE_LOCKING we could go over this limit and cause system boot-up problems.
+ * So, reduce the static allocations for lockdeps related structures so that
+ * everything fits in current required size limit.
+ */
+#ifdef CONFIG_PROVE_LOCKING_SMALL
+/*
* MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies
* we track.
*
@@ -54,18 +62,24 @@ enum {
* table (if it's not there yet), and we check it for lock order
* conflicts and deadlocks.
*/
+#define MAX_LOCKDEP_ENTRIES 16384UL
+#define MAX_LOCKDEP_CHAINS_BITS 15
+#define MAX_STACK_TRACE_ENTRIES 262144UL
+#else
#define MAX_LOCKDEP_ENTRIES 32768UL
#define MAX_LOCKDEP_CHAINS_BITS 16
-#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
-
-#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
/*
* Stack-trace: tightly packed array of stack backtrace
* addresses. Protected by the hash_lock.
*/
#define MAX_STACK_TRACE_ENTRIES 524288UL
+#endif
+
+#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
+
+#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
extern struct list_head all_lock_classes;
extern struct lock_chain lock_chains[];
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b01e547d4d04..a6c8db1d62f6 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1085,6 +1085,9 @@ config PROVE_LOCKING
For more details, see Documentation/locking/lockdep-design.txt.
+config PROVE_LOCKING_SMALL
+ bool
+
config LOCKDEP
bool
depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT