Date: Tue, 12 May 2026 18:12:09 +0000 From: Mateusz Piotrowski <0mp@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 03bc95b060a9 - main - dtrace_dtmalloc.4: Document the DTrace dtmalloc provider Message-ID: <6a036d79.45867.754c40cd@gitrepo.freebsd.org>
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The branch main has been updated by 0mp: URL: https://cgit.FreeBSD.org/src/commit/?id=03bc95b060a91ed9d410270d00d1dd4f8edcdcc7 commit 03bc95b060a91ed9d410270d00d1dd4f8edcdcc7 Author: Mateusz Piotrowski <0mp@FreeBSD.org> AuthorDate: 2025-07-17 20:55:49 +0000 Commit: Mateusz Piotrowski <0mp@FreeBSD.org> CommitDate: 2026-05-12 18:03:11 +0000 dtrace_dtmalloc.4: Document the DTrace dtmalloc provider MFC after: 1 week Discussed with: christos, markj, ziaee Differential Revision: https://reviews.freebsd.org/D51396 --- cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 | 3 +- share/man/man4/Makefile | 1 + share/man/man4/dtrace_dtmalloc.4 | 132 +++++++++++++++++++++++++++ share/man/man9/malloc.9 | 3 +- 4 files changed, 137 insertions(+), 2 deletions(-) diff --git a/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 b/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 index e78b6e1875ae..ad639f337a72 100644 --- a/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 +++ b/cddl/contrib/opensolaris/cmd/dtrace/dtrace.1 @@ -20,7 +20,7 @@ .\" .\" $FreeBSD$ .\" -.Dd May 7, 2026 +.Dd May 12, 2026 .Dt DTRACE 1 .Os .Sh NAME @@ -1298,6 +1298,7 @@ in .Xr dtrace_audit 4 , .Xr dtrace_callout_execute 4 , .Xr dtrace_cam 4 , +.Xr dtrace_dtmalloc 4 , .Xr dtrace_dtrace 4 , .Xr dtrace_fbt 4 , .Xr dtrace_io 4 , diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile index b9c441e97597..4f067f3ef757 100644 --- a/share/man/man4/Makefile +++ b/share/man/man4/Makefile @@ -1017,6 +1017,7 @@ _ccd.4= ccd.4 _dtrace_provs= dtrace_audit.4 \ dtrace_callout_execute.4 \ dtrace_cam.4 \ + dtrace_dtmalloc.4 \ dtrace_dtrace.4 \ dtrace_fbt.4 \ dtrace_io.4 \ diff --git a/share/man/man4/dtrace_dtmalloc.4 b/share/man/man4/dtrace_dtmalloc.4 new file mode 100644 index 000000000000..97b4ffd8a057 --- /dev/null +++ b/share/man/man4/dtrace_dtmalloc.4 @@ -0,0 +1,132 @@ +.\" +.\" Copyright (c) 2025-2026 Mateusz Piotrowski <0mp@FreeBSD.org> +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.Dd May 12, 2026 +.Dt DTRACE_DTMALLOC 4 +.Os +.Sh NAME +.Nm dtrace_dtmalloc +.Nd a DTrace provider for tracing kernel memory allocations by type +.Sh SYNOPSIS +.Nm dtmalloc Ns Cm :: Ns Ar function Ns Cm :malloc +.Nm dtmalloc Ns Cm :: Ns Ar function Ns Cm :free +.Sh DESCRIPTION +The +.Nm dtmalloc +provider instruments +.Xr malloc 9 +and +.Xr free 9 +kernel functions to trace memory allocations by type. +Refer to +.Xr malloc 9 +for more details about malloc types. +.Pp +The +.Nm dtmalloc Ns Cm :: Ns Ar function Ns Cm :malloc +probe fires upon a successful allocation. +Its probe arguments are: +.Bl -column -offset indent "malloc Probe Argument" "Definition" +.It Sy Probe Argument Ta Sy Definition +.It Fa args[0] Ta Ft struct malloc_type *mtp +.It Fa args[1] Ta Ft struct malloc_type_internal *mtip +.It Fa args[2] Ta Ft struct malloc_type_stats *mtsp +.It Fa args[3] Ta Ft unsigned long size +.It Fa args[4] Ta Ft int zindx +.El +.Pp +The +.Nm dtmalloc Ns Cm :: Ns Ar function Ns Cm :free +probe fires upon a free operation. +Its probe arguments are: +.Bl -column -offset indent "free Probe Argument" "Definition" +.It Sy free Probe Argument Ta Sy Definition +.It Fa args[0] Ta Ft struct malloc_type *mtp +.It Fa args[1] Ta Ft struct malloc_type_internal *mtip +.It Fa args[2] Ta Ft struct malloc_type_stats *mtsp +.It Fa args[3] Ta Ft unsigned long size +.It Fa args[4] Ta Always 0 +.El +.Pp +The first three arguments for each probe +.Po i.e., +.Fa mtp , mtip , +and +.Fa mtsp Pc +provide references to the +.Xr malloc 9 +type internals; +.Fa size +is the size of the allocation; +.Fa zindx +is the index into the +.Va kmemzones[] +array used for the allocation. +In practice, +.Fa size +is the most useful parameter to trace. +.Sh IMPLEMENTATION NOTES +The +.Ar function +part of the probe description in the +.Nm dtmalloc +provider is the +.Xr malloc 9 +type short description with all whitespace characters replaced +with underscores. +For example, a malloc type defined by +.Bd -literal -offset indent +MALLOC_DEFINE(M_FOO_BAR, "foo bar", "FooBar subsystem"); +.Ed +.Pp +will have probes called +.Bd -literal -offset indent +dtmalloc::foo_bar: +.Ed +.Sh FILES +.Bl -tag -width "<sys/malloc.h>" +.It In sys/malloc.h +The header where +.Vt struct malloc_type +is defined. +.El +.Sh EXAMPLES +.Ss Example 1 : Counting Successful Memory Allocations by Type +.Bd -literal -offset 2n +# dtrace -n 'dtmalloc:::malloc {@[stringof args[0]->ks_shortdesc] = count()}' +dtrace: description 'dtmalloc:::malloc ' matched 480 probes +^C + 80211node 1 + CAM CCB 1 + CAM periph 1 + ioctlops 1 + netlink 1 + soname 4 + sysctltmp 4 + solaris 5 + acpica 16 + temp 36 + lkpikmalloc 44 + iov 100 + selfd 648 +.Ed +.Sh SEE ALSO +.Xr dtrace 1 , +.Xr tracing 7 , +.Xr malloc 9 +.Sh AUTHORS +.An -nosplit +.Nm +was written by +.An John Birrell Aq Mt jb@FreeBSD.org . +.Pp +This manual page was written by +.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org . +.Sh CAVEATS +The +.Nm dtmalloc +provider does not trace +.Xr uma 9 +allocations. diff --git a/share/man/man9/malloc.9 b/share/man/man9/malloc.9 index 06f5ed4ef360..269a766e6168 100644 --- a/share/man/man9/malloc.9 +++ b/share/man/man9/malloc.9 @@ -28,7 +28,7 @@ .\" .\" $NetBSD: malloc.9,v 1.3 1996/11/11 00:05:11 lukem Exp $ .\" -.Dd August 4, 2024 +.Dd May 12, 2026 .Dt MALLOC 9 .Os .Sh NAME @@ -394,6 +394,7 @@ functions. Failing consistency checks will cause a panic or a system console message. .Sh SEE ALSO +.Xr dtrace_dtmalloc 4 , .Xr numa 4 , .Xr vmstat 8 , .Xr contigmalloc 9 ,home | help
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