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author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 23:11:48 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-06 23:11:48 +0300 |
commit | 2c6a392cddacde153865b15e8295ad0a35ed3c02 (patch) | |
tree | 558c34595f8987c87d26fc0fa0dc644fca9ef2cd /drivers/gpu | |
parent | 0a499fc5c37e6db096969a83534fd98a2bf2b36c (diff) | |
parent | 3599fe12a125fa7118da2bcc5033d7741fb5f3a1 (diff) | |
download | linux-2c6a392cddacde153865b15e8295ad0a35ed3c02.tar.xz |
Merge branch 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull stack trace updates from Ingo Molnar:
"So Thomas looked at the stacktrace code recently and noticed a few
weirdnesses, and we all know how such stories of crummy kernel code
meeting German engineering perfection end: a 45-patch series to clean
it all up! :-)
Here's the changes in Thomas's words:
'Struct stack_trace is a sinkhole for input and output parameters
which is largely pointless for most usage sites. In fact if embedded
into other data structures it creates indirections and extra storage
overhead for no benefit.
Looking at all usage sites makes it clear that they just require an
interface which is based on a storage array. That array is either on
stack, global or embedded into some other data structure.
Some of the stack depot usage sites are outright wrong, but
fortunately the wrongness just causes more stack being used for
nothing and does not have functional impact.
Another oddity is the inconsistent termination of the stack trace
with ULONG_MAX. It's pointless as the number of entries is what
determines the length of the stored trace. In fact quite some call
sites remove the ULONG_MAX marker afterwards with or without nasty
comments about it. Not all architectures do that and those which do,
do it inconsistenly either conditional on nr_entries == 0 or
unconditionally.
The following series cleans that up by:
1) Removing the ULONG_MAX termination in the architecture code
2) Removing the ULONG_MAX fixups at the call sites
3) Providing plain storage array based interfaces for stacktrace
and stackdepot.
4) Cleaning up the mess at the callsites including some related
cleanups.
5) Removing the struct stack_trace based interfaces
This is not changing the struct stack_trace interfaces at the
architecture level, but it removes the exposure to the generic
code'"
* 'core-stacktrace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
x86/stacktrace: Use common infrastructure
stacktrace: Provide common infrastructure
lib/stackdepot: Remove obsolete functions
stacktrace: Remove obsolete functions
livepatch: Simplify stack trace retrieval
tracing: Remove the last struct stack_trace usage
tracing: Simplify stack trace retrieval
tracing: Make ftrace_trace_userstack() static and conditional
tracing: Use percpu stack trace buffer more intelligently
tracing: Simplify stacktrace retrieval in histograms
lockdep: Simplify stack trace handling
lockdep: Remove save argument from check_prev_add()
lockdep: Remove unused trace argument from print_circular_bug()
drm: Simplify stacktrace handling
dm persistent data: Simplify stack trace handling
dm bufio: Simplify stack trace retrieval
btrfs: ref-verify: Simplify stack trace retrieval
dma/debug: Simplify stracktrace retrieval
fault-inject: Simplify stacktrace retrieval
mm/page_owner: Simplify stack trace handling
...
Diffstat (limited to 'drivers/gpu')
-rw-r--r-- | drivers/gpu/drm/drm_mm.c | 25 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/i915_vma.c | 11 | ||||
-rw-r--r-- | drivers/gpu/drm/i915/intel_runtime_pm.c | 25 |
3 files changed, 18 insertions, 43 deletions
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 2b4f373736c7..8b4cd31ce7bd 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -106,25 +106,19 @@ static noinline void save_stack(struct drm_mm_node *node) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH, - .skip = 1 - }; + unsigned int n; - save_stack_trace(&trace); - if (trace.nr_entries != 0 && - trace.entries[trace.nr_entries-1] == ULONG_MAX) - trace.nr_entries--; + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); /* May be called under spinlock, so avoid sleeping */ - node->stack = depot_save_stack(&trace, GFP_NOWAIT); + node->stack = stack_depot_save(entries, n, GFP_NOWAIT); } static void show_leaks(struct drm_mm *mm) { struct drm_mm_node *node; - unsigned long entries[STACKDEPTH]; + unsigned long *entries; + unsigned int nr_entries; char *buf; buf = kmalloc(BUFSZ, GFP_KERNEL); @@ -132,19 +126,14 @@ static void show_leaks(struct drm_mm *mm) return; list_for_each_entry(node, drm_mm_nodes(mm), node_list) { - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH - }; - if (!node->stack) { DRM_ERROR("node [%08llx + %08llx]: unknown owner\n", node->start, node->size); continue; } - depot_fetch_stack(node->stack, &trace); - snprint_stack_trace(buf, BUFSZ, &trace, 0); + nr_entries = stack_depot_fetch(node->stack, &entries); + stack_trace_snprint(buf, BUFSZ, entries, nr_entries, 0); DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s", node->start, node->size, buf); } diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c index b713bed20c38..41b5bcb803cb 100644 --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -36,11 +36,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason) { - unsigned long entries[12]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; char buf[512]; if (!vma->node.stack) { @@ -49,8 +46,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason) return; } - depot_fetch_stack(vma->node.stack, &trace); - snprint_stack_trace(buf, sizeof(buf), &trace, 0); + nr_entries = stack_depot_fetch(vma->node.stack, &entries); + stack_trace_snprint(buf, sizeof(buf), entries, nr_entries, 0); DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n", vma->node.start, vma->node.size, reason, buf); } diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c index a017a4232c0f..20c4434474e3 100644 --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -60,31 +60,20 @@ static noinline depot_stack_handle_t __save_depot_stack(void) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - .skip = 1, - }; + unsigned int n; - save_stack_trace(&trace); - if (trace.nr_entries && - trace.entries[trace.nr_entries - 1] == ULONG_MAX) - trace.nr_entries--; - - return depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN); + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); + return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); } static void __print_depot_stack(depot_stack_handle_t stack, char *buf, int sz, int indent) { - unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; - depot_fetch_stack(stack, &trace); - snprint_stack_trace(buf, sz, &trace, indent); + nr_entries = stack_depot_fetch(stack, &entries); + stack_trace_snprint(buf, sz, entries, nr_entries, indent); } static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915) |