git: e0ae2b39aa3e - stable/13 - pmc_allocate(3): document the count argument

[Mitchell Horne]

The branch stable/13 has been updated by mhorne:

URL: https://cgit.FreeBSD.org/src/commit/?id=e0ae2b39aa3e51b0e3f7b9661192cba8f06e7b10

commit e0ae2b39aa3e51b0e3f7b9661192cba8f06e7b10
Author:     Mitchell Horne <mhorne at FreeBSD.org>
AuthorDate: 2021-04-21 20:27:49 +0000
Commit:     Mitchell Horne <mhorne at FreeBSD.org>
CommitDate: 2021-04-29 13:13:57 +0000

    pmc_allocate(3): document the count argument
    
    This was added in b2ca2e50b9aa, and serves to provide an initial value
    to the PMC, eliminating the need for a second syscall via pmc_set(3).
    
    Reviewed by:    gnn, 0mp (manpages)
    MFC after:      1 week
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D29885
    
    (cherry picked from commit 50f6c139970084adeefec98c658645c34b72209e)
---
 lib/libpmc/pmc_allocate.3 | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/libpmc/pmc_allocate.3 b/lib/libpmc/pmc_allocate.3
index 291ca8ac0113..515b427cf7bc 100644
--- a/lib/libpmc/pmc_allocate.3
+++ b/lib/libpmc/pmc_allocate.3
@@ -23,7 +23,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 22, 2008
+.Dd April 21, 2021
 .Dt PMC_ALLOCATE 3
 .Os
 .Sh NAME
@@ -41,6 +41,7 @@
 .Fa "uint32_t flags"
 .Fa "int cpu"
 .Fa "pmc_id_t *pmcid"
+.Fa "uint64_t count"
 .Fc
 .Ft int
 .Fn pmc_release "pmc_id_t pmc"
@@ -111,6 +112,20 @@ Process scope PMC allocations should specify the constant
 .Dv PMC_CPU_ANY
 for this argument.
 .Pp
+The
+.Fa count
+argument behaves identically to the
+.Xr pmc_set 3
+function's
+.Fa value
+argument.
+For counting PMCs,
+.Fa count
+specifies the initial value of the allocated PMC.
+For sampling PMCs,
+.Fa count
+specifies the reload count.
+.Pp
 Function
 .Fn pmc_release
 releases the PMC denoted by argument