From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from NAM03-CO1-obe.outbound.protection.outlook.com (mail-co1nam03on0708.outbound.protection.outlook.com [IPv6:2a01:111:f400:fe48::708]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 423D8K2zJJzDqrV for ; Sun, 2 Sep 2018 23:14:24 +1000 (AEST) From: Sasha Levin To: "stable@vger.kernel.org" , "linux-kernel@vger.kernel.org" CC: Christophe Leroy , Alexander Shishkin , Peter Zijlstra , "linuxppc-dev@lists.ozlabs.org" , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH AUTOSEL 4.9 14/62] perf tools: Allow overriding MAX_NR_CPUS at compile time Date: Sun, 2 Sep 2018 13:14:19 +0000 Message-ID: <20180902131411.183978-4-alexander.levin@microsoft.com> References: <20180902131411.183978-1-alexander.levin@microsoft.com> In-Reply-To: <20180902131411.183978-1-alexander.levin@microsoft.com> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Christophe Leroy [ Upstream commit 21b8732eb4479b579bda9ee38e62b2c312c2a0e5 ] After update of kernel, the perf tool doesn't run anymore on my 32MB RAM powerpc board, but still runs on a 128MB RAM board: ~# strace perf execve("/usr/sbin/perf", ["perf"], [/* 12 vars */]) =3D -1 ENOMEM (Cannot= allocate memory) --- SIGSEGV {si_signo=3DSIGSEGV, si_code=3DSI_KERNEL, si_addr=3D0} --- +++ killed by SIGSEGV +++ Segmentation fault objdump -x shows that .bss section has a huge size of 24Mbytes: 27 .bss 016baca8 101cebb8 101cebb8 001cd988 2**3 With especially the following objects having quite big size: 10205f80 l O .bss 00140000 runtime_cycles_stats 10345f80 l O .bss 00140000 runtime_stalled_cycles_front_stats 10485f80 l O .bss 00140000 runtime_stalled_cycles_back_stats 105c5f80 l O .bss 00140000 runtime_branches_stats 10705f80 l O .bss 00140000 runtime_cacherefs_stats 10845f80 l O .bss 00140000 runtime_l1_dcache_stats 10985f80 l O .bss 00140000 runtime_l1_icache_stats 10ac5f80 l O .bss 00140000 runtime_ll_cache_stats 10c05f80 l O .bss 00140000 runtime_itlb_cache_stats 10d45f80 l O .bss 00140000 runtime_dtlb_cache_stats 10e85f80 l O .bss 00140000 runtime_cycles_in_tx_stats 10fc5f80 l O .bss 00140000 runtime_transaction_stats 11105f80 l O .bss 00140000 runtime_elision_stats 11245f80 l O .bss 00140000 runtime_topdown_total_slots 11385f80 l O .bss 00140000 runtime_topdown_slots_retired 114c5f80 l O .bss 00140000 runtime_topdown_slots_issued 11605f80 l O .bss 00140000 runtime_topdown_fetch_bubbles 11745f80 l O .bss 00140000 runtime_topdown_recovery_bubbles This is due to commit 4d255766d28b1 ("perf: Bump max number of cpus to 1024"), because many tables are sized with MAX_NR_CPUS This patch gives the opportunity to redefine MAX_NR_CPUS via $ make EXTRA_CFLAGS=3D-DMAX_NR_CPUS=3D1 Signed-off-by: Christophe Leroy Cc: Alexander Shishkin Cc: Peter Zijlstra Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/20170922112043.8349468C57@po15668-vm-win7.id= si0.si.c-s.fr Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/perf.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 9a0236a4cf95..8f8d895d5b74 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -22,7 +22,9 @@ static inline unsigned long long rdclock(void) return ts.tv_sec * 1000000000ULL + ts.tv_nsec; } =20 +#ifndef MAX_NR_CPUS #define MAX_NR_CPUS 1024 +#endif =20 extern const char *input_name; extern bool perf_host, perf_guest; --=20 2.17.1