Re: [PATCH 5/8] ring-buffer: Add ring_buffer_meta data
Hi Steven,
kernel test robot noticed the following build errors:
[auto build test ERROR on next-20240305]
[cannot apply to tip/x86/core akpm-mm/mm-everything linus/master v6.8-rc7
v6.8-rc6 v6.8-rc5 v6.8-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url:
https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/ring-buffer-Allow-mapped-field-to-be-set-without-mapping/20240306-100047
base: next-20240305
patch link:https://lore.kernel.org/r/20240306020006.100449500%40goodmis.org
patch subject: [PATCH 5/8] ring-buffer: Add ring_buffer_meta data
config: s390-defconfig
(https://download.01.org/0day-ci/archive/20240308/202403081843.qykjkyk4-...@intel.com/config)
compiler: clang version 19.0.0git (https://github.com/llvm/llvm-project
503c55e17037436dcd45ac69dea8967e67e3f5e8)
reproduce (this is a W=1 build):
(https://download.01.org/0day-ci/archive/20240308/202403081843.qykjkyk4-...@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot
| Closes:
https://lore.kernel.org/oe-kbuild-all/202403081843.qykjkyk4-...@intel.com/
All errors (new ones prefixed by >>):
In file included from kernel/trace/ring_buffer.c:8:
In file included from include/linux/trace_events.h:6:
In file included from include/linux/ring_buffer.h:5:
In file included from include/linux/mm.h:2208:
include/linux/vmstat.h:508:43: warning: arithmetic between different
enumeration types ('enum zone_stat_item' and 'enum numa_stat_item')
[-Wenum-enum-conversion]
508 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
|~ ^
509 |item];
|
include/linux/vmstat.h:515:43: warning: arithmetic between different
enumeration types ('enum zone_stat_item' and 'enum numa_stat_item')
[-Wenum-enum-conversion]
515 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
|~ ^
516 |NR_VM_NUMA_EVENT_ITEMS +
|~~
include/linux/vmstat.h:522:36: warning: arithmetic between different
enumeration types ('enum node_stat_item' and 'enum lru_list')
[-Wenum-enum-conversion]
522 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
| ~~~ ^ ~~~
include/linux/vmstat.h:527:43: warning: arithmetic between different
enumeration types ('enum zone_stat_item' and 'enum numa_stat_item')
[-Wenum-enum-conversion]
527 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
|~ ^
528 |NR_VM_NUMA_EVENT_ITEMS +
|~~
include/linux/vmstat.h:536:43: warning: arithmetic between different
enumeration types ('enum zone_stat_item' and 'enum numa_stat_item')
[-Wenum-enum-conversion]
536 | return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
|~ ^
537 |NR_VM_NUMA_EVENT_ITEMS +
|~~
In file included from kernel/trace/ring_buffer.c:8:
In file included from include/linux/trace_events.h:10:
In file included from include/linux/perf_event.h:62:
In file included from include/linux/security.h:35:
include/linux/bpf.h:736:48: warning: bitwise operation between different
enumeration types ('enum bpf_type_flag' and 'enum bpf_arg_type')
[-Wenum-enum-conversion]
736 | ARG_PTR_TO_MAP_VALUE_OR_NULL= PTR_MAYBE_NULL |
ARG_PTR_TO_MAP_VALUE,
| ~~ ^
include/linux/bpf.h:737:43: warning: bitwise operation between different
enumeration types ('enum bpf_type_flag' and 'enum bpf_arg_type')
[-Wenum-enum-conversion]
737 | ARG_PTR_TO_MEM_OR_NULL = PTR_MAYBE_NULL |
ARG_PTR_TO_MEM,
| ~~ ^
~~
include/linux/bpf.h:738:43: warning: bitwise operation between different
enumeration types ('enum bpf_type_flag' and 'enum bpf_arg_type')
[-Wenum-enum-conversion]
738 | ARG_PTR_TO_CTX_OR_NULL = PTR_MAYBE_NULL |
ARG_PTR_TO_CTX,
| ~~ ^
~~
include/linux/bpf.h:739:45: warning: bitwise operation between different
enumeration types ('enum bpf_type_flag' and 'enum bpf_arg_type')
[-Wenum-enum-conv
Re: [PATCH 5/8] ring-buffer: Add ring_buffer_meta data
Hi Steven,
kernel test robot noticed the following build warnings:
[auto build test WARNING on next-20240305]
[cannot apply to tip/x86/core akpm-mm/mm-everything linus/master v6.8-rc7
v6.8-rc6 v6.8-rc5 v6.8-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url:
https://github.com/intel-lab-lkp/linux/commits/Steven-Rostedt/ring-buffer-Allow-mapped-field-to-be-set-without-mapping/20240306-100047
base: next-20240305
patch link:https://lore.kernel.org/r/20240306020006.100449500%40goodmis.org
patch subject: [PATCH 5/8] ring-buffer: Add ring_buffer_meta data
config: sh-defconfig
(https://download.01.org/0day-ci/archive/20240308/202403081831.ewsqpo2a-...@intel.com/config)
compiler: sh4-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build):
(https://download.01.org/0day-ci/archive/20240308/202403081831.ewsqpo2a-...@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot
| Closes:
https://lore.kernel.org/oe-kbuild-all/202403081831.ewsqpo2a-...@intel.com/
All warnings (new ones prefixed by >>):
kernel/trace/ring_buffer.c: In function 'rb_set_commit_to_write':
>> kernel/trace/ring_buffer.c:3224:45: warning: assignment to 'long unsigned
>> int' from 'struct buffer_data_page *' makes integer from pointer without a
>> cast [-Wint-conversion]
3224 | meta->commit_buffer =
cpu_buffer->commit_page->page;
| ^
vim +3224 kernel/trace/ring_buffer.c
3192
3193 static __always_inline void
3194 rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
3195 {
3196 unsigned long max_count;
3197
3198 /*
3199 * We only race with interrupts and NMIs on this CPU.
3200 * If we own the commit event, then we can commit
3201 * all others that interrupted us, since the interruptions
3202 * are in stack format (they finish before they come
3203 * back to us). This allows us to do a simple loop to
3204 * assign the commit to the tail.
3205 */
3206 again:
3207 max_count = cpu_buffer->nr_pages * 100;
3208
3209 while (cpu_buffer->commit_page !=
READ_ONCE(cpu_buffer->tail_page)) {
3210 if (RB_WARN_ON(cpu_buffer, !(--max_count)))
3211 return;
3212 if (RB_WARN_ON(cpu_buffer,
3213
rb_is_reader_page(cpu_buffer->tail_page)))
3214 return;
3215 /*
3216 * No need for a memory barrier here, as the update
3217 * of the tail_page did it for this page.
3218 */
3219 local_set(_buffer->commit_page->page->commit,
3220rb_page_write(cpu_buffer->commit_page));
3221 rb_inc_page(_buffer->commit_page);
3222 if (cpu_buffer->ring_meta) {
3223 struct ring_buffer_meta *meta =
cpu_buffer->ring_meta;
> 3224 meta->commit_buffer =
> cpu_buffer->commit_page->page;
3225 }
3226 /* add barrier to keep gcc from optimizing too much */
3227 barrier();
3228 }
3229 while (rb_commit_index(cpu_buffer) !=
3230 rb_page_write(cpu_buffer->commit_page)) {
3231
3232 /* Make sure the readers see the content of what is
committed. */
3233 smp_wmb();
3234 local_set(_buffer->commit_page->page->commit,
3235rb_page_write(cpu_buffer->commit_page));
3236 RB_WARN_ON(cpu_buffer,
3237
local_read(_buffer->commit_page->page->commit) &
3238 ~RB_WRITE_MASK);
3239 barrier();
3240 }
3241
3242 /* again, keep gcc from optimizing */
3243 barrier();
3244
3245 /*
3246 * If an interrupt came in just after the first while loop
3247 * and pushed the tail page forward, we will be left with
3248 * a dangling commit that will never go forward.
3249 */
3250 if (unlikely(cpu_buffer->commit_page !=
READ_ONCE(cpu_buffer->tail_page)))
3251 goto again;
3252 }
3253
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
[PATCH 5/8] ring-buffer: Add ring_buffer_meta data
From: "Steven Rostedt (Google)"
Populate the ring_buffer_meta array. It holds the pointer to the
head_buffer (next to read), the commit_buffer (next to write) the size of
the sub-buffers, number of sub-buffers and an array that keeps track of
the order of the sub-buffers.
This information will be stored in the persistent memory to help on reboot
to reconstruct the ring buffer.
Signed-off-by: Steven Rostedt (Google)
---
kernel/trace/ring_buffer.c | 207 -
1 file changed, 182 insertions(+), 25 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 367597dc766b..5a90ada49366 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -42,6 +42,11 @@
static void update_pages_handler(struct work_struct *work);
struct ring_buffer_meta {
+ unsigned long head_buffer;
+ unsigned long commit_buffer;
+ __u32 subbuf_size;
+ __u32 nr_subbufs;
+ int buffers[];
};
/*
@@ -497,6 +502,7 @@ struct ring_buffer_per_cpu {
struct mutexmapping_lock;
unsigned long *subbuf_ids;/* ID to subbuf addr */
struct trace_buffer_meta*meta_page;
+ struct ring_buffer_meta *ring_meta;
/* ring buffer pages to update, > 0 to add, < 0 to remove */
longnr_pages_to_update;
@@ -1206,6 +1212,11 @@ static void rb_head_page_activate(struct
ring_buffer_per_cpu *cpu_buffer)
* Set the previous list pointer to have the HEAD flag.
*/
rb_set_list_to_head(head->list.prev);
+
+ if (cpu_buffer->ring_meta) {
+ struct ring_buffer_meta *meta = cpu_buffer->ring_meta;
+ meta->head_buffer = (unsigned long)head->page;
+ }
}
static void rb_list_head_clear(struct list_head *list)
@@ -1453,50 +1464,124 @@ rb_range_align_subbuf(unsigned long addr, int
subbuf_size, int nr_subbufs)
}
/*
- * Return a specific sub-buffer for a given @cpu defined by @idx.
+ * Return the ring_buffer_meta for a given @cpu.
*/
-static void *rb_range_buffer(struct trace_buffer *buffer, int cpu, int
nr_pages, int idx)
+static void *rb_range_meta(struct trace_buffer *buffer, int nr_pages, int cpu)
{
- unsigned long ptr;
int subbuf_size = buffer->subbuf_size + BUF_PAGE_HDR_SIZE;
+ unsigned long ptr = buffer->range_addr_start;
+ struct ring_buffer_meta *meta;
int nr_subbufs;
- /* Include the reader page */
- nr_subbufs = nr_pages + 1;
+ if (!ptr)
+ return NULL;
+
+ /* When nr_pages passed in is zero, the first meta has already been
initialized */
+ if (!nr_pages) {
+ meta = (struct ring_buffer_meta *)ptr;
+ nr_subbufs = meta->nr_subbufs;
+ } else {
+ meta = NULL;
+ /* Include the reader page */
+ nr_subbufs = nr_pages + 1;
+ }
/*
* The first chunk may not be subbuffer aligned, where as
* the rest of the chunks are.
*/
- ptr = buffer->range_addr_start;
- ptr = rb_range_align_subbuf(ptr, subbuf_size, nr_subbufs);
if (cpu) {
- unsigned long p;
-
- ptr += subbuf_size * nr_subbufs;
-
- /* Save the beginning of this CPU chunk */
- p = ptr;
-
ptr = rb_range_align_subbuf(ptr, subbuf_size, nr_subbufs);
+ ptr += subbuf_size * nr_subbufs;
if (cpu > 1) {
unsigned long size;
+ unsigned long p;
+ /* Save the beginning of this CPU chunk */
+ p = ptr;
+ ptr = rb_range_align_subbuf(ptr, subbuf_size,
nr_subbufs);
ptr += subbuf_size * nr_subbufs;
/* Now all chunks after this are the same size */
size = ptr - p;
ptr += size * (cpu - 2);
-
- ptr = rb_range_align_subbuf(ptr, subbuf_size,
nr_subbufs);
}
}
- if (ptr + subbuf_size * nr_subbufs > buffer->range_addr_end)
+ return (void *)ptr;
+}
+
+static void *rb_subbufs_from_meta(struct ring_buffer_meta *meta)
+{
+ int subbuf_size = meta->subbuf_size;
+ unsigned long ptr;
+
+ ptr = (unsigned long)meta;
+ ptr = rb_range_align_subbuf(ptr, subbuf_size, meta->nr_subbufs);
+
+ return (void *)ptr;
+}
+
+/*
+ * Return a specific sub-buffer for a given @cpu defined by @idx.
+ */
+static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx)
+{
+ struct ring_buffer_meta *meta;
+ unsigned long ptr;
+ int subbuf_size;
+
+ meta = rb_range_meta(cpu_buffer->buffer, 0, cpu_buffer->cpu);
+ if (!meta)
+ return NULL;
+
+ if (WARN_ON_ONCE(idx
