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Add patch to fix epoll lockdep warnings 

make debug as we're still really early in the release
This commit is contained in:
Josh Boyer 2011-08-02 14:33:26 -04:00
parent a145ed9864
commit ec0811cedb
5 changed files with 180 additions and 58 deletions
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8
config-generic
View File

@ -1472,12 +1472,12 @@ CONFIG_ATMEL=m
CONFIG_B43=m
CONFIG_B43_PCMCIA=y
CONFIG_B43_SDIO=y
# CONFIG_B43_DEBUG is not set
CONFIG_B43_DEBUG=y
CONFIG_B43_PHY_LP=y
CONFIG_B43_PHY_N=y
# CONFIG_B43_FORCE_PIO is not set
CONFIG_B43LEGACY=m
# CONFIG_B43LEGACY_DEBUG is not set
CONFIG_B43LEGACY_DEBUG=y
CONFIG_B43LEGACY_DMA=y
CONFIG_B43LEGACY_PIO=y
CONFIG_B43LEGACY_DMA_AND_PIO_MODE=y
@ -4004,7 +4004,7 @@ CONFIG_IBMASR=m
CONFIG_PM_DEBUG=y
CONFIG_PM_TRACE=y
# CONFIG_PM_VERBOSE is not set
# CONFIG_PM_TEST_SUSPEND is not set
CONFIG_PM_TEST_SUSPEND=y
CONFIG_PM_RUNTIME=y
CONFIG_CPU_FREQ=y
@ -4483,7 +4483,7 @@ CONFIG_USB_ATMEL=m
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
# CONFIG_DEBUG_BLOCK_EXT_DEVT is not set
# CONFIG_FUNCTION_GRAPH_TRACER is not set
# CONFIG_BOOT_TRACER is not set
CONFIG_BOOT_TRACER=y
CONFIG_EARLY_PRINTK_DBGP=y
CONFIG_SECURITYFS=y

102
config-nodebug
View File

@ -2,99 +2,99 @@ CONFIG_SND_VERBOSE_PRINTK=y
CONFIG_SND_DEBUG=y
CONFIG_SND_PCM_XRUN_DEBUG=y
# CONFIG_DEBUG_MUTEXES is not set
# CONFIG_DEBUG_RT_MUTEXES is not set
# CONFIG_DEBUG_LOCK_ALLOC is not set
# CONFIG_PROVE_LOCKING is not set
# CONFIG_DEBUG_VM is not set
# CONFIG_DEBUG_SPINLOCK is not set
# CONFIG_PROVE_RCU is not set
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_PROVE_RCU=y
# CONFIG_PROVE_RCU_REPEATEDLY is not set
# CONFIG_DEBUG_PER_CPU_MAPS is not set
CONFIG_DEBUG_PER_CPU_MAPS=y
CONFIG_CPUMASK_OFFSTACK=y
# CONFIG_CPU_NOTIFIER_ERROR_INJECT is not set
CONFIG_CPU_NOTIFIER_ERROR_INJECT=m
# CONFIG_FAULT_INJECTION is not set
# CONFIG_FAILSLAB is not set
# CONFIG_FAIL_PAGE_ALLOC is not set
# CONFIG_FAIL_MAKE_REQUEST is not set
# CONFIG_FAULT_INJECTION_DEBUG_FS is not set
# CONFIG_FAULT_INJECTION_STACKTRACE_FILTER is not set
# CONFIG_FAIL_IO_TIMEOUT is not set
CONFIG_FAULT_INJECTION=y
CONFIG_FAILSLAB=y
CONFIG_FAIL_PAGE_ALLOC=y
CONFIG_FAIL_MAKE_REQUEST=y
CONFIG_FAULT_INJECTION_DEBUG_FS=y
CONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y
CONFIG_FAIL_IO_TIMEOUT=y
# CONFIG_SLUB_DEBUG_ON is not set
CONFIG_SLUB_DEBUG_ON=y
# CONFIG_LOCK_STAT is not set
CONFIG_LOCK_STAT=y
# CONFIG_DEBUG_STACK_USAGE is not set
CONFIG_DEBUG_STACK_USAGE=y
# CONFIG_ACPI_DEBUG is not set
CONFIG_ACPI_DEBUG=y
# CONFIG_ACPI_DEBUG_FUNC_TRACE is not set
# CONFIG_DEBUG_SG is not set
CONFIG_DEBUG_SG=y
# CONFIG_DEBUG_PAGEALLOC is not set
# CONFIG_DEBUG_WRITECOUNT is not set
# CONFIG_DEBUG_OBJECTS is not set
CONFIG_DEBUG_WRITECOUNT=y
CONFIG_DEBUG_OBJECTS=y
# CONFIG_DEBUG_OBJECTS_SELFTEST is not set
# CONFIG_DEBUG_OBJECTS_FREE is not set
# CONFIG_DEBUG_OBJECTS_TIMERS is not set
# CONFIG_DEBUG_OBJECTS_RCU_HEAD is not set
CONFIG_DEBUG_OBJECTS_FREE=y
CONFIG_DEBUG_OBJECTS_TIMERS=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1
# CONFIG_X86_PTDUMP is not set
CONFIG_X86_PTDUMP=y
# CONFIG_CAN_DEBUG_DEVICES is not set
CONFIG_CAN_DEBUG_DEVICES=y
# CONFIG_MODULE_FORCE_UNLOAD is not set
CONFIG_MODULE_FORCE_UNLOAD=y
# CONFIG_SYSCTL_SYSCALL_CHECK is not set
CONFIG_SYSCTL_SYSCALL_CHECK=y
# CONFIG_DEBUG_NOTIFIERS is not set
CONFIG_DEBUG_NOTIFIERS=y
# CONFIG_DMA_API_DEBUG is not set
CONFIG_DMA_API_DEBUG=y
# CONFIG_MMIOTRACE is not set
CONFIG_MMIOTRACE=y
# CONFIG_DEBUG_CREDENTIALS is not set
CONFIG_DEBUG_CREDENTIALS=y
# off in both production debug and nodebug builds,
# on in rawhide nodebug builds
# CONFIG_DEBUG_FORCE_WEAK_PER_CPU is not set
CONFIG_DEBUG_FORCE_WEAK_PER_CPU=y
# CONFIG_EXT4_DEBUG is not set
CONFIG_EXT4_DEBUG=y
# CONFIG_DEBUG_PERF_USE_VMALLOC is not set
CONFIG_DEBUG_PERF_USE_VMALLOC=y
# CONFIG_JBD2_DEBUG is not set
CONFIG_JBD2_DEBUG=y
# CONFIG_DEBUG_CFQ_IOSCHED is not set
CONFIG_DEBUG_CFQ_IOSCHED=y
# CONFIG_DRBD_FAULT_INJECTION is not set
CONFIG_DRBD_FAULT_INJECTION=y
# CONFIG_ATH_DEBUG is not set
# CONFIG_CARL9170_DEBUGFS is not set
# CONFIG_IWLWIFI_DEVICE_TRACING is not set
CONFIG_ATH_DEBUG=y
CONFIG_CARL9170_DEBUGFS=y
CONFIG_IWLWIFI_DEVICE_TRACING=y
# CONFIG_DEBUG_OBJECTS_WORK is not set
CONFIG_DEBUG_OBJECTS_WORK=y
# CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is not set
# CONFIG_DMADEVICES_DEBUG is not set
# CONFIG_DMADEVICES_VDEBUG is not set
CONFIG_DMADEVICES_DEBUG=y
CONFIG_DMADEVICES_VDEBUG=y
CONFIG_PM_ADVANCED_DEBUG=y
# CONFIG_CEPH_LIB_PRETTYDEBUG is not set
# CONFIG_QUOTA_DEBUG is not set
CONFIG_CEPH_LIB_PRETTYDEBUG=y
CONFIG_QUOTA_DEBUG=y
CONFIG_PCI_DEFAULT_USE_CRS=y
CONFIG_KGDB_KDB=y
CONFIG_KDB_KEYBOARD=y
# CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER is not set
# CONFIG_TEST_LIST_SORT is not set
CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER=y
CONFIG_TEST_LIST_SORT=y
# CONFIG_DEBUG_SET_MODULE_RONX is not set
CONFIG_DEBUG_SET_MODULE_RONX=y

2
config-x86_64-generic
View File

@ -16,7 +16,7 @@ CONFIG_K8_NUMA=y
CONFIG_AMD_NUMA=y
CONFIG_X86_64_ACPI_NUMA=y
# CONFIG_NUMA_EMU is not set
CONFIG_NR_CPUS=256
CONFIG_NR_CPUS=512
CONFIG_X86_POWERNOW_K8=m
CONFIG_X86_P4_CLOCKMOD=m
CONFIG_IA32_EMULATION=y

116
epoll-fix-spurious-lockdep-warnings.patch Normal file
View File

@ -0,0 +1,116 @@
epoll can acquire multiple ep->mutex on multiple "struct eventpoll"s
at once in the case where one epoll fd is monitoring another epoll
fd. This is perfectly OK, since we're careful about the lock ordering,
but causes spurious lockdep warnings. Annotate the recursion using
mutex_lock_nested, and add a comment explaining the nesting rules for
good measure.
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Nelson Elhage <nelhage@nelhage.com>
---
I've tested this on a synthetic epoll test case, that just adds e1 to
e2 and then does an epoll_wait(). I verified that it caused lockdep
problems on 3.0 and that this patch fixed it, but I haven't done more
extensive testing. Paul, are you able to test systemd against this?
fs/eventpoll.c | 25 ++++++++++++++++++-------
1 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index f9cfd16..0cb7bc6 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -76,6 +76,15 @@
* Events that require holding "epmutex" are very rare, while for
* normal operations the epoll private "ep->mtx" will guarantee
* a better scalability.
+ * It is possible to acquire multiple "ep->mtx"es at once in the case
+ * when one epoll fd is added to another. In this case, we always
+ * acquire the locks in the order of nesting (i.e. after epoll_ctl(e1,
+ * EPOLL_CTL_ADD, e2), e1->mtx will always be acquired before
+ * e2->mtx). Since we disallow cycles of epoll file descriptors, this
+ * ensures that the mutexes are well-ordered. In order to communicate
+ * this nesting to lockdep, when walking a tree of epoll file
+ * descriptors, we use the current recursion depth as the lockdep
+ * subkey.
*/
/* Epoll private bits inside the event mask */
@@ -464,13 +473,15 @@ static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
* @ep: Pointer to the epoll private data structure.
* @sproc: Pointer to the scan callback.
* @priv: Private opaque data passed to the @sproc callback.
+ * @depth: The current depth of recursive f_op->poll calls.
*
* Returns: The same integer error code returned by the @sproc callback.
*/
static int ep_scan_ready_list(struct eventpoll *ep,
int (*sproc)(struct eventpoll *,
struct list_head *, void *),
- void *priv)
+ void *priv,
+ int depth)
{
int error, pwake = 0;
unsigned long flags;
@@ -481,7 +492,7 @@ static int ep_scan_ready_list(struct eventpoll *ep,
* We need to lock this because we could be hit by
* eventpoll_release_file() and epoll_ctl().
*/
- mutex_lock(&ep->mtx);
+ mutex_lock_nested(&ep->mtx, depth);
/*
* Steal the ready list, and re-init the original one to the
@@ -670,7 +681,7 @@ static int ep_read_events_proc(struct eventpoll *ep, struct list_head *head,
static int ep_poll_readyevents_proc(void *priv, void *cookie, int call_nests)
{
- return ep_scan_ready_list(priv, ep_read_events_proc, NULL);
+ return ep_scan_ready_list(priv, ep_read_events_proc, NULL, call_nests + 1);
}
static unsigned int ep_eventpoll_poll(struct file *file, poll_table *wait)
@@ -737,7 +748,7 @@ void eventpoll_release_file(struct file *file)
ep = epi->ep;
list_del_init(&epi->fllink);
- mutex_lock(&ep->mtx);
+ mutex_lock_nested(&ep->mtx, 0);
ep_remove(ep, epi);
mutex_unlock(&ep->mtx);
}
@@ -1134,7 +1145,7 @@ static int ep_send_events(struct eventpoll *ep,
esed.maxevents = maxevents;
esed.events = events;
- return ep_scan_ready_list(ep, ep_send_events_proc, &esed);
+ return ep_scan_ready_list(ep, ep_send_events_proc, &esed, 0);
}
static inline struct timespec ep_set_mstimeout(long ms)
@@ -1267,7 +1278,7 @@ static int ep_loop_check_proc(void *priv, void *cookie, int call_nests)
struct rb_node *rbp;
struct epitem *epi;
- mutex_lock(&ep->mtx);
+ mutex_lock_nested(&ep->mtx, call_nests + 1);
for (rbp = rb_first(&ep->rbr); rbp; rbp = rb_next(rbp)) {
epi = rb_entry(rbp, struct epitem, rbn);
if (unlikely(is_file_epoll(epi->ffd.file))) {
@@ -1409,7 +1420,7 @@ SYSCALL_DEFINE4(epoll_ctl, int, epfd, int, op, int, fd,
}
- mutex_lock(&ep->mtx);
+ mutex_lock_nested(&ep->mtx, 0);
/*
* Try to lookup the file inside our RB tree, Since we grabbed "mtx"
--
1.7.4.1
--
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10
kernel.spec
View File

@ -131,7 +131,7 @@ Summary: The Linux kernel
%define doc_build_fail true
%endif
%define rawhide_skip_docs 0
%define rawhide_skip_docs 1
%if 0%{?rawhide_skip_docs}
%define with_doc 0
%define doc_build_fail true
@ -154,7 +154,7 @@ Summary: The Linux kernel
# Set debugbuildsenabled to 1 for production (build separate debug kernels)
# and 0 for rawhide (all kernels are debug kernels).
# See also 'make debug' and 'make release'.
%define debugbuildsenabled 1
%define debugbuildsenabled 0
# Want to build a vanilla kernel build without any non-upstream patches?
%define with_vanilla %{?_with_vanilla: 1} %{?!_with_vanilla: 0}
@ -696,6 +696,7 @@ Patch12205: runtime_pm_fixups.patch
Patch12303: dmar-disable-when-ricoh-multifunction.patch
Patch13000: fix-scsi_dispatch_cmd.patch
Patch13001: epoll-fix-spurious-lockdep-warnings.patch
Patch20000: utrace.patch
@ -1280,6 +1281,7 @@ ApplyPatch udlfb-bind-framebuffer-to-interface.patch
ApplyPatch dmar-disable-when-ricoh-multifunction.patch
ApplyPatch fix-scsi_dispatch_cmd.patch
ApplyPatch epoll-fix-spurious-lockdep-warnings.patch
# utrace.
ApplyPatch utrace.patch
@ -1893,6 +1895,10 @@ fi
# and build.
%changelog
* Tue Aug 02 2011 Josh Boyer <jwboyer@redhat.com>
- Fix epoll recursive lockdep warnings (rhbz 722472)
- Turn debug builds back on
* Tue Aug 02 2011 Josh Boyer <jwboyer@redhat.com>
- Add change from Yanko Kaneti to get the rt2x00 drivers in modules.networking
(rhbz 708314)