Re: [PATCH 1/1 fyi] tools headers UAPI: Sync files changed by new cachestat syscall with the kernel sources

From: Nhat Pham
Date: Tue Jul 11 2023 - 14:57:15 EST


On Tue, Jul 11, 2023 at 7:38 AM Arnaldo Carvalho de Melo
<arnaldo.melo@xxxxxxxxx> wrote:
>
> tldr; Just FYI, I'm carrying this on the perf tools tree.
>
> - Arnaldo
>
> Full explanation:
>
> There used to be no copies, with tools/ code using kernel headers
> directly. From time to time tools/perf/ broke due to legitimate kernel
> hacking. At some point Linus complained about such direct usage. Then we
> adopted the current model.
>
> The way these headers are used in perf are not restricted to just
> including them to compile something.
>
> There are sometimes used in scripts that convert defines into string
> tables, etc, so some change may break one of these scripts, or new MSRs
> may use some different #define pattern, etc.
>
> E.g.:
>
> $ ls -1 tools/perf/trace/beauty/*.sh | head -5
> tools/perf/trace/beauty/arch_errno_names.sh
> tools/perf/trace/beauty/drm_ioctl.sh
> tools/perf/trace/beauty/fadvise.sh
> tools/perf/trace/beauty/fsconfig.sh
> tools/perf/trace/beauty/fsmount.sh
> $
> $ tools/perf/trace/beauty/fadvise.sh
> static const char *fadvise_advices[] = {
> [0] = "NORMAL",
> [1] = "RANDOM",
> [2] = "SEQUENTIAL",
> [3] = "WILLNEED",
> [4] = "DONTNEED",
> [5] = "NOREUSE",
> };
> $
>
> The tools/perf/check-headers.sh script, part of the tools/ build
> process, points out changes in the original files.
>
> So its important not to touch the copies in tools/ when doing changes in
> the original kernel headers, that will be done later, when
> check-headers.sh inform about the change to the perf tools hackers.
>
> ---
>
> To pick the changes in these csets:
>
> cf264e1329fb0307 ("cachestat: implement cachestat syscall")
>
> That add support for this new syscall in tools such as 'perf trace'.
>
> For instance, this is now possible:
>
> # perf trace -e cachestat
> ^C[root@five ~]#
> # perf trace -v -e cachestat
> Using CPUID AuthenticAMD-25-21-0
> event qualifier tracepoint filter: (common_pid != 3163687 && common_pid != 3147) && (id == 451)
> mmap size 528384B
> ^C[root@five ~]
>
> # perf trace -v -e *stat* --max-events=10
> Using CPUID AuthenticAMD-25-21-0
> event qualifier tracepoint filter: (common_pid != 3163713 && common_pid != 3147) && (id == 4 || id == 5 || id == 6 || id == 136 || id == 137 || id == 138 || id == 262 || id == 332 || id == 451)
> mmap size 528384B
> 0.000 ( 0.009 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b60) = 0
> 0.012 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
> 0.036 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256f0, flag: 4096) = 0
> 0.372 ( 0.006 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b10) = 0
> 0.379 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
> 0.390 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256a0, flag: 4096) = 0
> 0.609 ( 0.005 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b60) = 0
> 0.615 ( 0.003 ms): Cache2 I/O/4544 newfstatat(dfd: CWD, filename: 0x45635288, statbuf: 0x7f874569d250) = 0
> 0.625 ( 0.002 ms): Cache2 I/O/4544 newfstatat(dfd: 138, filename: 0x541b7093, statbuf: 0x7f87457256f0, flag: 4096) = 0
> 0.826 ( 0.005 ms): Cache2 I/O/4544 statfs(pathname: 0x45635288, buf: 0x7f8745725b10) = 0
> #
>
> That is the filter expression attached to the raw_syscalls:sys_{enter,exit}
> tracepoints.
>
> $ find tools/perf/arch/ -name "syscall*tbl" | xargs grep -w sys_cachestat
> tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl:451 n64 cachestat sys_cachestat
> tools/perf/arch/powerpc/entry/syscalls/syscall.tbl:451 common cachestat sys_cachestat
> tools/perf/arch/s390/entry/syscalls/syscall.tbl:451 common cachestat sys_cachestat sys_cachestat
> tools/perf/arch/x86/entry/syscalls/syscall_64.tbl:451 common cachestat sys_cachestat
> $
>
> $ grep -w cachestat /tmp/build/perf-tools/arch/x86/include/generated/asm/syscalls_64.c
> [451] = "cachestat",
> $
>
> This addresses these perf build warnings:
>
> Warning: Kernel ABI header differences:
> diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
> diff -u tools/include/uapi/linux/mman.h include/uapi/linux/mman.h
> diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
> diff -u tools/perf/arch/powerpc/entry/syscalls/syscall.tbl arch/powerpc/kernel/syscalls/syscall.tbl
> diff -u tools/perf/arch/s390/entry/syscalls/syscall.tbl arch/s390/kernel/syscalls/syscall.tbl
> diff -u tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl arch/mips/kernel/syscalls/syscall_n64.tbl
>
> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Ian Rogers <irogers@xxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Nhat Pham <nphamcs@xxxxxxxxx>
> Link: https://lore.kernel.org/lkml/
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
> tools/include/uapi/asm-generic/unistd.h | 5 ++++-
> tools/include/uapi/linux/mman.h | 14 ++++++++++++++
> .../perf/arch/mips/entry/syscalls/syscall_n64.tbl | 1 +
> tools/perf/arch/powerpc/entry/syscalls/syscall.tbl | 1 +
> tools/perf/arch/s390/entry/syscalls/syscall.tbl | 1 +
> tools/perf/arch/x86/entry/syscalls/syscall_64.tbl | 1 +
> 6 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h
> index dd7d8e10f16d83a1..fd6c1cb585db43c4 100644
> --- a/tools/include/uapi/asm-generic/unistd.h
> +++ b/tools/include/uapi/asm-generic/unistd.h
> @@ -817,8 +817,11 @@ __SYSCALL(__NR_futex_waitv, sys_futex_waitv)
> #define __NR_set_mempolicy_home_node 450
> __SYSCALL(__NR_set_mempolicy_home_node, sys_set_mempolicy_home_node)
>
> +#define __NR_cachestat 451
> +__SYSCALL(__NR_cachestat, sys_cachestat)
> +
> #undef __NR_syscalls
> -#define __NR_syscalls 451
> +#define __NR_syscalls 452
>
> /*
> * 32 bit systems traditionally used different
> diff --git a/tools/include/uapi/linux/mman.h b/tools/include/uapi/linux/mman.h
> index f55bc680b5b0a45e..a246e11988d5e0e2 100644
> --- a/tools/include/uapi/linux/mman.h
> +++ b/tools/include/uapi/linux/mman.h
> @@ -4,6 +4,7 @@
>
> #include <asm/mman.h>
> #include <asm-generic/hugetlb_encode.h>
> +#include <linux/types.h>
>
> #define MREMAP_MAYMOVE 1
> #define MREMAP_FIXED 2
> @@ -41,4 +42,17 @@
> #define MAP_HUGE_2GB HUGETLB_FLAG_ENCODE_2GB
> #define MAP_HUGE_16GB HUGETLB_FLAG_ENCODE_16GB
>
> +struct cachestat_range {
> + __u64 off;
> + __u64 len;
> +};
> +
> +struct cachestat {
> + __u64 nr_cache;
> + __u64 nr_dirty;
> + __u64 nr_writeback;
> + __u64 nr_evicted;
> + __u64 nr_recently_evicted;
> +};
> +
> #endif /* _UAPI_LINUX_MMAN_H */
> diff --git a/tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl b/tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl
> index 3f1886ad9d8060b4..cfda2511badf3ad0 100644
> --- a/tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl
> +++ b/tools/perf/arch/mips/entry/syscalls/syscall_n64.tbl
> @@ -365,3 +365,4 @@
> 448 n64 process_mrelease sys_process_mrelease
> 449 n64 futex_waitv sys_futex_waitv
> 450 common set_mempolicy_home_node sys_set_mempolicy_home_node
> +451 n64 cachestat sys_cachestat
> diff --git a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> index a0be127475b1f761..8c0b08b7a80ec4b7 100644
> --- a/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> +++ b/tools/perf/arch/powerpc/entry/syscalls/syscall.tbl
> @@ -537,3 +537,4 @@
> 448 common process_mrelease sys_process_mrelease
> 449 common futex_waitv sys_futex_waitv
> 450 nospu set_mempolicy_home_node sys_set_mempolicy_home_node
> +451 common cachestat sys_cachestat
> diff --git a/tools/perf/arch/s390/entry/syscalls/syscall.tbl b/tools/perf/arch/s390/entry/syscalls/syscall.tbl
> index b68f47541169f9af..a6935af2235cab6c 100644
> --- a/tools/perf/arch/s390/entry/syscalls/syscall.tbl
> +++ b/tools/perf/arch/s390/entry/syscalls/syscall.tbl
> @@ -453,3 +453,4 @@
> 448 common process_mrelease sys_process_mrelease sys_process_mrelease
> 449 common futex_waitv sys_futex_waitv sys_futex_waitv
> 450 common set_mempolicy_home_node sys_set_mempolicy_home_node sys_set_mempolicy_home_node
> +451 common cachestat sys_cachestat sys_cachestat
> diff --git a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
> index c84d12608cd2de9e..227538b0ce801eeb 100644
> --- a/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
> +++ b/tools/perf/arch/x86/entry/syscalls/syscall_64.tbl
> @@ -372,6 +372,7 @@
> 448 common process_mrelease sys_process_mrelease
> 449 common futex_waitv sys_futex_waitv
> 450 common set_mempolicy_home_node sys_set_mempolicy_home_node
> +451 common cachestat sys_cachestat
>
> #
> # Due to a historical design error, certain syscalls are numbered differently
> --
> 2.37.1
>

LGTM.
Acked-by: Nhat Pham <nphamcs@xxxxxxxxx>