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207f7df727
Knowing the topology of online CPUs is useful for more than just expr literals. Move to a global function that caches the value. An additional upside is that this may also avoid computing the CPU topology in some situations. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Cc: Caleb Biggers <caleb.biggers@intel.com> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Florian Fischer <florian.fischer@muhq.space> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jing Zhang <renyu.zj@linux.alibaba.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Kajol Jain <kjain@linux.ibm.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Perry Taylor <perry.taylor@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Stephane Eranian <eranian@google.com> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-stm32@st-md-mailman.stormreply.com Link: https://lore.kernel.org/r/20230219092848.639226-8-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
36 lines
850 B
C
36 lines
850 B
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <string.h>
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#include "api/fs/fs.h"
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#include "cputopo.h"
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#include "smt.h"
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bool smt_on(void)
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{
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static bool cached;
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static bool cached_result;
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int fs_value;
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if (cached)
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return cached_result;
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if (sysfs__read_int("devices/system/cpu/smt/active", &fs_value) >= 0)
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cached_result = (fs_value == 1);
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else
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cached_result = cpu_topology__smt_on(online_topology());
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cached = true;
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return cached_result;
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}
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bool core_wide(bool system_wide, const char *user_requested_cpu_list)
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{
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/* If not everything running on a core is being recorded then we can't use core_wide. */
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if (!system_wide)
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return false;
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/* Cheap case that SMT is disabled and therefore we're inherently core_wide. */
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if (!smt_on())
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return true;
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return cpu_topology__core_wide(online_topology(), user_requested_cpu_list);
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}
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