Messages in this thread | | | Date | Tue, 9 Feb 2021 09:46:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf report: Fix arm64 gap between kernel start and module end |
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Em Tue, Feb 09, 2021 at 09:40:09AM -0300, Arnaldo Carvalho de Melo escreveu: > Em Mon, Mar 30, 2020 at 10:18:10AM -0300, Arnaldo Carvalho de Melo escreveu: > > Em Mon, Mar 30, 2020 at 10:11:29AM -0300, Arnaldo Carvalho de Melo escreveu: > > > Em Mon, Mar 30, 2020 at 03:41:11PM +0800, Kemeng Shi escreveu: > > > > diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build > > > > index 393b9895c..37cbfa5e9 100644 > > > > --- a/tools/perf/arch/arm64/util/Build > > > > +++ b/tools/perf/arch/arm64/util/Build > > > > @@ -2,6 +2,7 @@ libperf-y += header.o > > > > libperf-y += tsc.o > > > > libperf-y += sym-handling.o > > > > libperf-y += kvm-stat.o > > > > +libperf-y += machine.o > > > > > > You made the patch against an old perf codebase, right? This libperf-y > > > above was changed to perf-y here: > > > > > > commit 5ff328836dfde0cef9f28c8b8791a90a36d7a183 > > > Author: Jiri Olsa <jolsa@kernel.org> > > > Date: Wed Feb 13 13:32:39 2019 +0100 > > > > > > perf tools: Rename build libperf to perf > > > > > > ---- > > > > > > I'm fixing this up, please check my perf/core branch later to see that > > > all is working as intended. > > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git perf/core > > > > Here it is: > > > > > > From 829b915d7d7eeafbe4af76dce19ccbdc743a43c8 Mon Sep 17 00:00:00 2001 > > From: Kemeng Shi <shikemeng@huawei.com> > > Date: Mon, 30 Mar 2020 15:41:11 +0800 > > Subject: [PATCH 1/1] perf symbols: Fix arm64 gap between kernel start and > > module end > > > > During execution of command 'perf report' in my arm64 virtual machine, > > this error message is showed: > > > > failed to process sample > > > > __symbol__inc_addr_samples(860): ENOMEM! sym->name=__this_module, > > start=0x1477100, addr=0x147dbd8, end=0x80002000, func: 0 > > > > The error is caused with path: > > cmd_report > > __cmd_report > > perf_session__process_events > > __perf_session__process_events > > ordered_events__flush > > __ordered_events__flush > > oe->deliver (ordered_events__deliver_event) > > perf_session__deliver_event > > machines__deliver_event > > perf_evlist__deliver_sample > > tool->sample (process_sample_event) > > hist_entry_iter__add > > iter->add_entry_cb(hist_iter__report_callback) > > hist_entry__inc_addr_samples > > symbol__inc_addr_samples > > __symbol__inc_addr_samples > > h = annotated_source__histogram(src, evidx) (NULL) > > > > annotated_source__histogram failed is caused with path: > > ... > > hist_entry__inc_addr_samples > > symbol__inc_addr_samples > > symbol__hists > > annotated_source__alloc_histograms > > src->histograms = calloc(nr_hists, sizeof_sym_hist) (failed) > > > > Calloc failed as the symbol__size(sym) is too huge. As show in error > > message: start=0x1477100, end=0x80002000, size of symbol is about 2G. > > > > This is the same problem as 'perf annotate: Fix s390 gap between kernel > > end and module start (b9c0a64901d5bd)'. Perf gets symbol information from > > /proc/kallsyms in __dso__load_kallsyms. A part of symbol in /proc/kallsyms > > from my virtual machine is as follows: > > #cat /proc/kallsyms | sort > > ... > > ffff000001475080 d rpfilter_mt_reg [ip6t_rpfilter] > > ffff000001475100 d $d [ip6t_rpfilter] > > ffff000001475100 d __this_module [ip6t_rpfilter] > > ffff000080080000 t _head > > ffff000080080000 T _text > > ffff000080080040 t pe_header > > ... > > > > Take line 'ffff000001475100 d __this_module [ip6t_rpfilter]' as example. > > The start and end of symbol are both set to ffff000001475100 in > > dso__load_all_kallsyms. Then symbols__fixup_end will set the end of symbol > > to next big address to ffff000001475100 in /proc/kallsyms, ffff000080080000 > > in this example. Then sizeof of symbol will be about 2G and cause the > > problem. > > > > The start of module in my machine is > > ffff000000a62000 t $x [dm_mod] > > > > The start of kernel in my machine is > > ffff000080080000 t _head > > > > There is a big gap between end of module and begin of kernel if a samll > > amount of memory is used by module. And the last symbol in module will > > have a large address range as caotaining the big gap. > > > > Give that the module and kernel text segment sequence may change in > > the future, fix this by limiting range of last symbol in module and kernel > > to 4K in arch arm64. > > > > Signed-off-by: Kemeng Shi <shikemeng@huawei.com> > > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > > Cc: Hu Shiyuan <hushiyuan@huawei.com> > > Cc: Ian Rogers <irogers@google.com> > > Cc: Jiri Olsa <jolsa@redhat.com> > > Cc: Mark Rutland <mark.rutland@arm.com> > > Cc: Namhyung Kim <namhyung@kernel.org> > > Cc: Nick Desaulniers <ndesaulniers@google.com> > > Cc: Peter Zijlstra <peterz@infradead.org> > > Cc: Thomas Richter <tmricht@linux.ibm.com> > > Cc: hewenliang4@huawei.com > > Link: http://lore.kernel.org/lkml/33fd24c4-0d5a-9d93-9b62-dffa97c992ca@huawei.com > > [ refreshed the patch on current codebase ] > > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > > --- > > tools/perf/arch/arm64/util/Build | 1 + > > tools/perf/arch/arm64/util/machine.c | 26 ++++++++++++++++++++++++++ > > 2 files changed, 27 insertions(+) > > create mode 100644 tools/perf/arch/arm64/util/machine.c > > > > diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build > > index 789956f76d85..5c13438c7bd4 100644 > > --- a/tools/perf/arch/arm64/util/Build > > +++ b/tools/perf/arch/arm64/util/Build > > @@ -1,4 +1,5 @@ > > perf-y += header.o > > +perf-y += machine.o > > perf-y += perf_regs.o > > perf-$(CONFIG_DWARF) += dwarf-regs.o > > perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o > > diff --git a/tools/perf/arch/arm64/util/machine.c b/tools/perf/arch/arm64/util/machine.c > > new file mode 100644 > > index 000000000000..94745131e89a > > --- /dev/null > > +++ b/tools/perf/arch/arm64/util/machine.c > > @@ -0,0 +1,26 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +#include <stdio.h> > > +#include "debug.h" > > +#include "symbol.h" > > + > > +/* On arm64, kernel text segment start at high memory address, > > + * for example 0xffff 0000 8xxx xxxx. Modules start at a low memory > > + * address, like 0xffff 0000 00ax xxxx. When only samll amount of > > + * memory is used by modules, gap between end of module's text segment > > + * and start of kernel text segment may be reach 2G. > > + * Therefore do not fill this gap and do not assign it to the kernel dso map. > > + */ > > + > > +#define SYMBOL_LIMIT (1 << 12) /* 4K */ > > + > > +void arch__symbols__fixup_end(struct symbol *p, struct symbol *c) > > +{ > > + if ((strchr(p->name, '[') && strchr(c->name, '[') == NULL) || > > + (strchr(p->name, '[') == NULL && strchr(c->name, '['))) > > + /* Limit range of last symbol in module and kernel */ > > + p->end += SYMBOL_LIMIT; > > + else > > + p->end = c->start; > > + pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end); > > +} > > This breaks the build on powerpc 32-bit, I'm fixing it using the proper "%#" PRIx64 " style. > > - Arnaldo
Sorry, the build broke on powerpc 32-bit, but the above for arm also has the same problem, I'll fix it there as well even it not breaking the build as that is 64-bit specific (ARM case).
- Arnaldo
> > 72 13.69 ubuntu:18.04-x-powerpc : FAIL powerpc-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 > arch/powerpc/util/machine.c: In function 'arch__symbols__fixup_end': > arch/powerpc/util/machine.c:23:12: error: format '%lx' expects argument of type 'long unsigned int', but argument 6 has type 'u64 {aka long long unsigned int}' [-Werror=format=] > pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end); > ^ > /git/linux/tools/perf/util/debug.h:18:21: note: in definition of macro 'pr_fmt' > #define pr_fmt(fmt) fmt > ^~~ > /git/linux/tools/perf/util/debug.h:33:29: note: in expansion of macro 'pr_debugN' > #define pr_debug4(fmt, ...) pr_debugN(4, pr_fmt(fmt), ##__VA_ARGS__) > ^~~~~~~~~ > /git/linux/tools/perf/util/debug.h:33:42: note: in expansion of macro 'pr_fmt' > #define pr_debug4(fmt, ...) pr_debugN(4, pr_fmt(fmt), ##__VA_ARGS__) > ^~~~~~ > arch/powerpc/util/machine.c:23:2: note: in expansion of macro 'pr_debug4' > pr_debug4("%s sym:%s end:%#lx\n", __func__, p->name, p->end); > ^~~~~~~~~ > cc1: all warnings being treated as errors > /git/linux/tools/build/Makefile.build:139: recipe for target 'util' failed > make[5]: *** [util] Error 2 > /git/linux/tools/build/Makefile.build:139: recipe for target 'powerpc' failed > make[4]: *** [powerpc] Error 2 > /git/linux/tools/build/Makefile.build:139: recipe for target 'arch' failed > make[3]: *** [arch] Error 2 > 73 30.47 ubuntu:18.04-x-powerpc64 : Ok powerpc64-linux-gnu-gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 >
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- Arnaldo
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