mirror of
https://github.com/torvalds/linux
synced 2024-11-05 18:23:50 +00:00
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
|
|
#include <string.h>
|
|
#include "api/fs/fs.h"
|
|
#include "cputopo.h"
|
|
#include "smt.h"
|
|
|
|
bool smt_on(void)
|
|
{
|
|
static bool cached;
|
|
static bool cached_result;
|
|
int fs_value;
|
|
|
|
if (cached)
|
|
return cached_result;
|
|
|
|
if (sysfs__read_int("devices/system/cpu/smt/active", &fs_value) >= 0)
|
|
cached_result = (fs_value == 1);
|
|
else
|
|
cached_result = cpu_topology__smt_on(online_topology());
|
|
|
|
cached = true;
|
|
return cached_result;
|
|
}
|
|
|
|
bool core_wide(bool system_wide, const char *user_requested_cpu_list)
|
|
{
|
|
/* If not everything running on a core is being recorded then we can't use core_wide. */
|
|
if (!system_wide)
|
|
return false;
|
|
|
|
/* Cheap case that SMT is disabled and therefore we're inherently core_wide. */
|
|
if (!smt_on())
|
|
return true;
|
|
|
|
return cpu_topology__core_wide(online_topology(), user_requested_cpu_list);
|
|
}
|