Em Wed, Jul 24, 2019 at 02:27:03PM +0200, Thomas Richter escreveu:
During execution of command 'perf top' the error message:
Not enough memory for annotating '__irf_end' symbol!)
is emitted from this call sequence: __cmd_top perf_top__mmap_read perf_top__mmap_read_idx perf_event__process_sample hist_entry_iter__add hist_iter__top_callback perf_top__record_precise_ip hist_entry__inc_addr_samples symbol__inc_addr_samples symbol__get_annotation symbol__alloc_hist
Thanks, applied.
- Arnaldo
In this function the size of symbol __irf_end is calculated. The size of a symbol is the difference between its start and end address. When the symbol was read the first time, its start and end was set to: symbol__new: __irf_end 0xe954d0-0xe954d0 which is correct and maps with /proc/kallsyms:
root@s8360046:~/linux-4.15.0/tools/perf# fgrep _irf_end /proc/kallsyms 0000000000e954d0 t __irf_end root@s8360046:~/linux-4.15.0/tools/perf#
In function symbol__alloc_hist() the end of symbol __irf_end is
symbol__alloc_hist sym:__irf_end start:0xe954d0 end:0x3ff80045a8
which is identical with the first module entry in /proc/kallsyms
This results in a symbol size of __irf_req for histogram analyses of 70334140059072 bytes and a malloc() for this requested size fails.
The root cause of this is function __dso__load_kallsyms() +-> symbols__fixup_end()
Function symbols__fixup_end() enlarges the last symbol in the kallsyms map # fgrep __irf_end /proc/kallsyms 0000000000e954d0 t __irf_end #
to the start address of the first module: # cat /proc/kallsyms | sort | egrep ' [tT] ' .... 0000000000e952d0 T __security_initcall_end 0000000000e954d0 T __initramfs_size 0000000000e954d0 t __irf_end 000003ff800045a8 T fc_get_event_number [scsi_transport_fc] 000003ff800045d0 t store_fc_vport_disable [scsi_transport_fc] 000003ff800046a8 T scsi_is_fc_rport [scsi_transport_fc] 000003ff800046d0 t fc_target_setup [scsi_transport_fc]
On s390 the kernel is located around memory address 0x200, 0x10000 or 0x100000, depending on linux version. Modules however start some- where around 0x3ff xxxx xxxx.
This is different than x86 and produces a large gap for which histogram allocation fails.
Fix this by detecting the kernel's last symbol and do no adjustment for it. Introduce a weak function and handle s390 specifics.
Cc: stable@vger.kernel.org Reported-by: Klaus Theurich klaus.theurich@de.ibm.com Signed-off-by: Thomas Richter tmricht@linux.ibm.com Acked-by: Heiko Carstens heiko.carstens@de.ibm.com
tools/perf/arch/s390/util/machine.c | 17 +++++++++++++++++ tools/perf/util/symbol.c | 7 ++++++- tools/perf/util/symbol.h | 1 + 3 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/tools/perf/arch/s390/util/machine.c b/tools/perf/arch/s390/util/machine.c index de26b1441a48..c8c86a0c9b79 100644 --- a/tools/perf/arch/s390/util/machine.c +++ b/tools/perf/arch/s390/util/machine.c @@ -6,6 +6,7 @@ #include "machine.h" #include "api/fs/fs.h" #include "debug.h" +#include "symbol.h" int arch__fix_module_text_start(u64 *start, u64 *size, const char *name) { @@ -33,3 +34,19 @@ int arch__fix_module_text_start(u64 *start, u64 *size, const char *name) return 0; }
+/* On s390 kernel text segment start is located at very low memory addresses,
- for example 0x10000. Modules are located at very high memory addresses,
- for example 0x3ff xxxx xxxx. The gap between end of kernel text segment
- and beginning of first module's text segment is very big.
- Therefore do not fill this gap and do not assign it to the kernel dso map.
- */
+void arch__symbols__fixup_end(struct symbol *p, struct symbol *c) +{
- if (strchr(p->name, '[') == NULL && strchr(c->name, '['))
/* Last kernel symbol mapped to end of page */p->end = roundup(p->end, page_size);- else
p->end = c->start;- pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end);
+} diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 5cbad55cd99d..3b49eb4e3ed9 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -91,6 +91,11 @@ static int prefix_underscores_count(const char *str) return tail - str; } +void __weak arch__symbols__fixup_end(struct symbol *p, struct symbol *c) +{
- p->end = c->start;
+}
const char * __weak arch__normalize_symbol_name(const char *name) { return name; @@ -217,7 +222,7 @@ void symbols__fixup_end(struct rb_root_cached *symbols) curr = rb_entry(nd, struct symbol, rb_node); if (prev->end == prev->start && prev->end != curr->start)
prev->end = curr->start;
arch__symbols__fixup_end(prev, curr);/* Last entry */ diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index 9a8fe012910a..f30ab608ea54 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -277,6 +277,7 @@ const char *arch__normalize_symbol_name(const char *name); #define SYMBOL_A 0 #define SYMBOL_B 1 +void arch__symbols__fixup_end(struct symbol *p, struct symbol *c); int arch__compare_symbol_names(const char *namea, const char *nameb); int arch__compare_symbol_names_n(const char *namea, const char *nameb, unsigned int n); -- 2.21.0