git: c514a571af74 - main - hwpmc: split out PMC_OP_PMCALLOCATE
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Wed, 14 Jun 2023 16:46:43 UTC
The branch main has been updated by mhorne:
URL: https://cgit.FreeBSD.org/src/commit/?id=c514a571af74429d9f2a0e9e1118e0903906c4de
commit c514a571af74429d9f2a0e9e1118e0903906c4de
Author: Mitchell Horne <mhorne@FreeBSD.org>
AuthorDate: 2023-06-14 16:33:27 +0000
Commit: Mitchell Horne <mhorne@FreeBSD.org>
CommitDate: 2023-06-14 16:34:21 +0000
hwpmc: split out PMC_OP_PMCALLOCATE
Split out the large chunk of functional logic from the syscall handler
into a helper function. This keeps it separate from the syscall
control-flow logic, resulting in better readability overall. It also
wins back a level of indentation.
Flip the return values of the pmc_can_allocate_row() and
pmc_can_allocate_rowindex() functions to boolean types, like their
naming implies. We weren't actually using the error codes they were
returning.
While here, make some small style cleanups. No functional change
intended.
Reviewed by: jkoshy
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D40292
---
sys/dev/hwpmc/hwpmc_mod.c | 521 +++++++++++++++++++++++-----------------------
1 file changed, 256 insertions(+), 265 deletions(-)
diff --git a/sys/dev/hwpmc/hwpmc_mod.c b/sys/dev/hwpmc/hwpmc_mod.c
index 24cd3ba0fc0f..fb6aa3ad4588 100644
--- a/sys/dev/hwpmc/hwpmc_mod.c
+++ b/sys/dev/hwpmc/hwpmc_mod.c
@@ -210,7 +210,8 @@ static int pmc_attach_process(struct proc *p, struct pmc *pm);
static struct pmc *pmc_allocate_pmc_descriptor(void);
static struct pmc_owner *pmc_allocate_owner_descriptor(struct proc *p);
static int pmc_attach_one_process(struct proc *p, struct pmc *pm);
-static int pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
+static bool pmc_can_allocate_row(int ri, enum pmc_mode mode);
+static bool pmc_can_allocate_rowindex(struct proc *p, unsigned int ri,
int cpu);
static int pmc_can_attach(struct pmc *pm, struct proc *p);
static void pmc_capture_user_callchain(int cpu, int soft,
@@ -2904,7 +2905,7 @@ pmc_getrowdisp(int ri)
* - the current process has already allocated a PMC at index 'ri'
* via OP_ALLOCATE.
*/
-static int
+static bool
pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
{
struct pmc *pm;
@@ -2927,10 +2928,10 @@ pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
if (PMC_TO_ROWINDEX(pm) == ri) {
mode = PMC_TO_MODE(pm);
if (PMC_IS_VIRTUAL_MODE(mode))
- return (EEXIST);
+ return (false);
if (PMC_IS_SYSTEM_MODE(mode) &&
PMC_TO_CPU(pm) == cpu)
- return (EEXIST);
+ return (false);
}
}
}
@@ -2941,18 +2942,18 @@ pmc_can_allocate_rowindex(struct proc *p, unsigned int ri, int cpu)
*/
if ((pp = pmc_find_process_descriptor(p, 0)) != NULL)
if (pp->pp_pmcs[ri].pp_pmc != NULL)
- return (EEXIST);
+ return (false);
PMCDBG4(PMC,ALR,2, "can-allocate-rowindex proc=%p (%d, %s) ri=%d ok",
p, p->p_pid, p->p_comm, ri);
- return (0);
+ return (true);
}
/*
* Check if a given PMC at row index 'ri' can be currently used in
* mode 'mode'.
*/
-static int
+static bool
pmc_can_allocate_row(int ri, enum pmc_mode mode)
{
enum pmc_disp disp;
@@ -2979,13 +2980,13 @@ pmc_can_allocate_row(int ri, enum pmc_mode mode)
if (!PMC_ROW_DISP_IS_FREE(ri) &&
!(disp == PMC_DISP_THREAD && PMC_ROW_DISP_IS_THREAD(ri)) &&
!(disp == PMC_DISP_STANDALONE && PMC_ROW_DISP_IS_STANDALONE(ri)))
- return (EBUSY);
+ return (false);
/*
* All OK
*/
PMCDBG2(PMC,ALR,2, "can-allocate-row ri=%d mode=%d ok", ri, mode);
- return (0);
+ return (true);
}
/*
@@ -3282,6 +3283,248 @@ static const char *pmc_op_to_name[] = {
is_sx_downgraded = true; \
} while (0)
+/*
+ * Main body of PMC_OP_PMCALLOCATE.
+ */
+static int
+pmc_do_op_pmcallocate(struct thread *td, struct pmc_op_pmcallocate *pa)
+{
+ struct proc *p;
+ struct pmc *pmc;
+ struct pmc_binding pb;
+ struct pmc_classdep *pcd;
+ struct pmc_hw *phw;
+ enum pmc_mode mode;
+ enum pmc_class class;
+ uint32_t caps;
+ u_int cpu;
+ int adjri, n;
+ int error;
+
+ class = pa->pm_class;
+ caps = pa->pm_caps;
+ mode = pa->pm_mode;
+ cpu = pa->pm_cpu;
+
+ p = td->td_proc;
+
+ /* Requested mode must exist. */
+ if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC &&
+ mode != PMC_MODE_TS && mode != PMC_MODE_TC))
+ return (EINVAL);
+
+ /* Requested CPU must be valid. */
+ if (cpu != PMC_CPU_ANY && cpu >= pmc_cpu_max())
+ return (EINVAL);
+
+ /*
+ * Virtual PMCs should only ask for a default CPU.
+ * System mode PMCs need to specify a non-default CPU.
+ */
+ if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != PMC_CPU_ANY) ||
+ (PMC_IS_SYSTEM_MODE(mode) && cpu == PMC_CPU_ANY))
+ return (EINVAL);
+
+ /*
+ * Check that an inactive CPU is not being asked for.
+ */
+ if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu))
+ return (ENXIO);
+
+ /*
+ * Refuse an allocation for a system-wide PMC if this process has been
+ * jailed, or if this process lacks super-user credentials and the
+ * sysctl tunable 'security.bsd.unprivileged_syspmcs' is zero.
+ */
+ if (PMC_IS_SYSTEM_MODE(mode)) {
+ if (jailed(td->td_ucred))
+ return (EPERM);
+ if (!pmc_unprivileged_syspmcs) {
+ error = priv_check(td, PRIV_PMC_SYSTEM);
+ if (error != 0)
+ return (error);
+ }
+ }
+
+ /*
+ * Look for valid values for 'pm_flags'.
+ */
+ if ((pa->pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
+ PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) != 0)
+ return (EINVAL);
+
+ /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN. */
+ if ((pa->pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) ==
+ PMC_F_USERCALLCHAIN)
+ return (EINVAL);
+
+ /* PMC_F_USERCALLCHAIN is only valid for sampling mode. */
+ if ((pa->pm_flags & PMC_F_USERCALLCHAIN) != 0 && mode != PMC_MODE_TS &&
+ mode != PMC_MODE_SS)
+ return (EINVAL);
+
+ /* Process logging options are not allowed for system PMCs. */
+ if (PMC_IS_SYSTEM_MODE(mode) &&
+ (pa->pm_flags & (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT)) != 0)
+ return (EINVAL);
+
+ /*
+ * All sampling mode PMCs need to be able to interrupt the CPU.
+ */
+ if (PMC_IS_SAMPLING_MODE(mode))
+ caps |= PMC_CAP_INTERRUPT;
+
+ /* A valid class specifier should have been passed in. */
+ pcd = pmc_class_to_classdep(class);
+ if (pcd == NULL)
+ return (EINVAL);
+
+ /* The requested PMC capabilities should be feasible. */
+ if ((pcd->pcd_caps & caps) != caps)
+ return (EOPNOTSUPP);
+
+ PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d", pa->pm_ev,
+ caps, mode, cpu);
+
+ pmc = pmc_allocate_pmc_descriptor();
+ pmc->pm_id = PMC_ID_MAKE_ID(cpu, pa->pm_mode, class, PMC_ID_INVALID);
+ pmc->pm_event = pa->pm_ev;
+ pmc->pm_state = PMC_STATE_FREE;
+ pmc->pm_caps = caps;
+ pmc->pm_flags = pa->pm_flags;
+
+ /* XXX set lower bound on sampling for process counters */
+ if (PMC_IS_SAMPLING_MODE(mode)) {
+ /*
+ * Don't permit requested sample rate to be less than
+ * pmc_mincount.
+ */
+ if (pa->pm_count < MAX(1, pmc_mincount))
+ log(LOG_WARNING, "pmcallocate: passed sample "
+ "rate %ju - setting to %u\n",
+ (uintmax_t)pa->pm_count,
+ MAX(1, pmc_mincount));
+ pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount),
+ pa->pm_count);
+ } else
+ pmc->pm_sc.pm_initial = pa->pm_count;
+
+ /* switch thread to CPU 'cpu' */
+ pmc_save_cpu_binding(&pb);
+
+#define PMC_IS_SHAREABLE_PMC(cpu, n) \
+ (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \
+ PMC_PHW_FLAG_IS_SHAREABLE)
+#define PMC_IS_UNALLOCATED(cpu, n) \
+ (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
+
+ if (PMC_IS_SYSTEM_MODE(mode)) {
+ pmc_select_cpu(cpu);
+ for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) {
+ pcd = pmc_ri_to_classdep(md, n, &adjri);
+
+ if (!pmc_can_allocate_row(n, mode) ||
+ !pmc_can_allocate_rowindex(p, n, cpu))
+ continue;
+ if (!PMC_IS_UNALLOCATED(cpu, n) &&
+ !PMC_IS_SHAREABLE_PMC(cpu, n))
+ continue;
+
+ if (pcd->pcd_allocate_pmc(cpu, adjri, pmc, pa) == 0) {
+ /* Success. */
+ break;
+ }
+ }
+ } else {
+ /* Process virtual mode */
+ for (n = pcd->pcd_ri; n < md->pmd_npmc; n++) {
+ pcd = pmc_ri_to_classdep(md, n, &adjri);
+
+ if (!pmc_can_allocate_row(n, mode) ||
+ !pmc_can_allocate_rowindex(p, n, PMC_CPU_ANY))
+ continue;
+
+ if (pcd->pcd_allocate_pmc(td->td_oncpu, adjri, pmc,
+ pa) == 0) {
+ /* Success. */
+ break;
+ }
+ }
+ }
+
+#undef PMC_IS_UNALLOCATED
+#undef PMC_IS_SHAREABLE_PMC
+
+ pmc_restore_cpu_binding(&pb);
+
+ if (n == md->pmd_npmc) {
+ pmc_destroy_pmc_descriptor(pmc);
+ return (EINVAL);
+ }
+
+ /* Fill in the correct value in the ID field. */
+ pmc->pm_id = PMC_ID_MAKE_ID(cpu, mode, class, n);
+
+ PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
+ pmc->pm_event, class, mode, n, pmc->pm_id);
+
+ /* Process mode PMCs with logging enabled need log files. */
+ if ((pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW)) != 0)
+ pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
+
+ /* All system mode sampling PMCs require a log file. */
+ if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
+ pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
+
+ /*
+ * Configure global pmc's immediately.
+ */
+ if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
+ pmc_save_cpu_binding(&pb);
+ pmc_select_cpu(cpu);
+
+ phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
+ pcd = pmc_ri_to_classdep(md, n, &adjri);
+
+ if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
+ (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
+ (void)pcd->pcd_release_pmc(cpu, adjri, pmc);
+ pmc_destroy_pmc_descriptor(pmc);
+ pmc_restore_cpu_binding(&pb);
+ return (EPERM);
+ }
+
+ pmc_restore_cpu_binding(&pb);
+ }
+
+ pmc->pm_state = PMC_STATE_ALLOCATED;
+ pmc->pm_class = class;
+
+ /*
+ * Mark row disposition.
+ */
+ if (PMC_IS_SYSTEM_MODE(mode))
+ PMC_MARK_ROW_STANDALONE(n);
+ else
+ PMC_MARK_ROW_THREAD(n);
+
+ /*
+ * Register this PMC with the current thread as its owner.
+ */
+ error = pmc_register_owner(p, pmc);
+ if (error != 0) {
+ pmc_release_pmc_descriptor(pmc);
+ pmc_destroy_pmc_descriptor(pmc);
+ return (error);
+ }
+
+ /*
+ * Return the allocated index.
+ */
+ pa->pm_pmcid = pmc->pm_id;
+ return (0);
+}
+
/*
* Main body of PMC_OP_PMCATTACH.
*/
@@ -3833,269 +4076,17 @@ pmc_syscall_handler(struct thread *td, void *syscall_args)
/*
* Allocate a PMC.
*/
-
case PMC_OP_PMCALLOCATE:
{
- int adjri, n;
- u_int cpu;
- uint32_t caps;
- struct pmc *pmc;
- enum pmc_mode mode;
- struct pmc_hw *phw;
- struct pmc_binding pb;
- struct pmc_classdep *pcd;
struct pmc_op_pmcallocate pa;
- if ((error = copyin(arg, &pa, sizeof(pa))) != 0)
- break;
-
- caps = pa.pm_caps;
- mode = pa.pm_mode;
- cpu = pa.pm_cpu;
-
- if ((mode != PMC_MODE_SS && mode != PMC_MODE_SC &&
- mode != PMC_MODE_TS && mode != PMC_MODE_TC) ||
- (cpu != (u_int) PMC_CPU_ANY && cpu >= pmc_cpu_max())) {
- error = EINVAL;
- break;
- }
-
- /*
- * Virtual PMCs should only ask for a default CPU.
- * System mode PMCs need to specify a non-default CPU.
- */
-
- if ((PMC_IS_VIRTUAL_MODE(mode) && cpu != (u_int) PMC_CPU_ANY) ||
- (PMC_IS_SYSTEM_MODE(mode) && cpu == (u_int) PMC_CPU_ANY)) {
- error = EINVAL;
- break;
- }
-
- /*
- * Check that an inactive CPU is not being asked for.
- */
-
- if (PMC_IS_SYSTEM_MODE(mode) && !pmc_cpu_is_active(cpu)) {
- error = ENXIO;
- break;
- }
-
- /*
- * Refuse an allocation for a system-wide PMC if this
- * process has been jailed, or if this process lacks
- * super-user credentials and the sysctl tunable
- * 'security.bsd.unprivileged_syspmcs' is zero.
- */
-
- if (PMC_IS_SYSTEM_MODE(mode)) {
- if (jailed(curthread->td_ucred)) {
- error = EPERM;
- break;
- }
- if (!pmc_unprivileged_syspmcs) {
- error = priv_check(curthread,
- PRIV_PMC_SYSTEM);
- if (error)
- break;
- }
- }
-
- /*
- * Look for valid values for 'pm_flags'
- */
-
- if ((pa.pm_flags & ~(PMC_F_DESCENDANTS | PMC_F_LOG_PROCCSW |
- PMC_F_LOG_PROCEXIT | PMC_F_CALLCHAIN |
- PMC_F_USERCALLCHAIN)) != 0) {
- error = EINVAL;
- break;
- }
-
- /* PMC_F_USERCALLCHAIN is only valid with PMC_F_CALLCHAIN */
- if ((pa.pm_flags & (PMC_F_CALLCHAIN | PMC_F_USERCALLCHAIN)) ==
- PMC_F_USERCALLCHAIN) {
- error = EINVAL;
- break;
- }
-
- /* PMC_F_USERCALLCHAIN is only valid for sampling mode */
- if (pa.pm_flags & PMC_F_USERCALLCHAIN &&
- mode != PMC_MODE_TS && mode != PMC_MODE_SS) {
- error = EINVAL;
- break;
- }
-
- /* process logging options are not allowed for system PMCs */
- if (PMC_IS_SYSTEM_MODE(mode) && (pa.pm_flags &
- (PMC_F_LOG_PROCCSW | PMC_F_LOG_PROCEXIT))) {
- error = EINVAL;
- break;
- }
-
- /*
- * All sampling mode PMCs need to be able to interrupt the
- * CPU.
- */
- if (PMC_IS_SAMPLING_MODE(mode))
- caps |= PMC_CAP_INTERRUPT;
-
- /* A valid class specifier should have been passed in. */
- pcd = pmc_class_to_classdep(pa.pm_class);
- if (pcd == NULL) {
- error = EINVAL;
- break;
- }
-
- /* The requested PMC capabilities should be feasible. */
- if ((pcd->pcd_caps & caps) != caps) {
- error = EOPNOTSUPP;
- break;
- }
-
- PMCDBG4(PMC,ALL,2, "event=%d caps=0x%x mode=%d cpu=%d",
- pa.pm_ev, caps, mode, cpu);
-
- pmc = pmc_allocate_pmc_descriptor();
- pmc->pm_id = PMC_ID_MAKE_ID(cpu,pa.pm_mode,pa.pm_class,
- PMC_ID_INVALID);
- pmc->pm_event = pa.pm_ev;
- pmc->pm_state = PMC_STATE_FREE;
- pmc->pm_caps = caps;
- pmc->pm_flags = pa.pm_flags;
-
- /* XXX set lower bound on sampling for process counters */
- if (PMC_IS_SAMPLING_MODE(mode)) {
- /*
- * Don't permit requested sample rate to be
- * less than pmc_mincount.
- */
- if (pa.pm_count < MAX(1, pmc_mincount))
- log(LOG_WARNING, "pmcallocate: passed sample "
- "rate %ju - setting to %u\n",
- (uintmax_t)pa.pm_count,
- MAX(1, pmc_mincount));
- pmc->pm_sc.pm_reloadcount = MAX(MAX(1, pmc_mincount),
- pa.pm_count);
- } else
- pmc->pm_sc.pm_initial = pa.pm_count;
-
- /* switch thread to CPU 'cpu' */
- pmc_save_cpu_binding(&pb);
-
-#define PMC_IS_SHAREABLE_PMC(cpu, n) \
- (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_state & \
- PMC_PHW_FLAG_IS_SHAREABLE)
-#define PMC_IS_UNALLOCATED(cpu, n) \
- (pmc_pcpu[(cpu)]->pc_hwpmcs[(n)]->phw_pmc == NULL)
-
- if (PMC_IS_SYSTEM_MODE(mode)) {
- pmc_select_cpu(cpu);
- for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
- pcd = pmc_ri_to_classdep(md, n, &adjri);
- if (pmc_can_allocate_row(n, mode) == 0 &&
- pmc_can_allocate_rowindex(
- curthread->td_proc, n, cpu) == 0 &&
- (PMC_IS_UNALLOCATED(cpu, n) ||
- PMC_IS_SHAREABLE_PMC(cpu, n)) &&
- pcd->pcd_allocate_pmc(cpu, adjri, pmc,
- &pa) == 0)
- break;
- }
- } else {
- /* Process virtual mode */
- for (n = pcd->pcd_ri; n < (int) md->pmd_npmc; n++) {
- pcd = pmc_ri_to_classdep(md, n, &adjri);
- if (pmc_can_allocate_row(n, mode) == 0 &&
- pmc_can_allocate_rowindex(
- curthread->td_proc, n,
- PMC_CPU_ANY) == 0 &&
- pcd->pcd_allocate_pmc(curthread->td_oncpu,
- adjri, pmc, &pa) == 0)
- break;
- }
- }
-
-#undef PMC_IS_UNALLOCATED
-#undef PMC_IS_SHAREABLE_PMC
-
- pmc_restore_cpu_binding(&pb);
-
- if (n == (int) md->pmd_npmc) {
- pmc_destroy_pmc_descriptor(pmc);
- pmc = NULL;
- error = EINVAL;
+ error = copyin(arg, &pa, sizeof(pa));
+ if (error != 0)
break;
- }
-
- /* Fill in the correct value in the ID field */
- pmc->pm_id = PMC_ID_MAKE_ID(cpu,mode,pa.pm_class,n);
-
- PMCDBG5(PMC,ALL,2, "ev=%d class=%d mode=%d n=%d -> pmcid=%x",
- pmc->pm_event, pa.pm_class, mode, n, pmc->pm_id);
-
- /* Process mode PMCs with logging enabled need log files */
- if (pmc->pm_flags & (PMC_F_LOG_PROCEXIT | PMC_F_LOG_PROCCSW))
- pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
- /* All system mode sampling PMCs require a log file */
- if (PMC_IS_SAMPLING_MODE(mode) && PMC_IS_SYSTEM_MODE(mode))
- pmc->pm_flags |= PMC_F_NEEDS_LOGFILE;
-
- /*
- * Configure global pmc's immediately
- */
-
- if (PMC_IS_SYSTEM_MODE(PMC_TO_MODE(pmc))) {
-
- pmc_save_cpu_binding(&pb);
- pmc_select_cpu(cpu);
-
- phw = pmc_pcpu[cpu]->pc_hwpmcs[n];
- pcd = pmc_ri_to_classdep(md, n, &adjri);
-
- if ((phw->phw_state & PMC_PHW_FLAG_IS_ENABLED) == 0 ||
- (error = pcd->pcd_config_pmc(cpu, adjri, pmc)) != 0) {
- (void)pcd->pcd_release_pmc(cpu, adjri, pmc);
- pmc_destroy_pmc_descriptor(pmc);
- pmc = NULL;
- pmc_restore_cpu_binding(&pb);
- error = EPERM;
- break;
- }
-
- pmc_restore_cpu_binding(&pb);
- }
-
- pmc->pm_state = PMC_STATE_ALLOCATED;
- pmc->pm_class = pa.pm_class;
-
- /*
- * mark row disposition
- */
-
- if (PMC_IS_SYSTEM_MODE(mode))
- PMC_MARK_ROW_STANDALONE(n);
- else
- PMC_MARK_ROW_THREAD(n);
-
- /*
- * Register this PMC with the current thread as its owner.
- */
-
- if ((error =
- pmc_register_owner(curthread->td_proc, pmc)) != 0) {
- pmc_release_pmc_descriptor(pmc);
- pmc_destroy_pmc_descriptor(pmc);
- pmc = NULL;
+ error = pmc_do_op_pmcallocate(td, &pa);
+ if (error != 0)
break;
- }
-
-
- /*
- * Return the allocated index.
- */
-
- pa.pm_pmcid = pmc->pm_id;
error = copyout(&pa, arg, sizeof(pa));
}