Re: [PATCH v2] LoongArch: Libvtv add loongarch support.

[Caroline Tice <cmtice@google.com>]

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On Tue, Sep 27, 2022 at 3:04 AM Lulu Cheng <chenglulu@loongson.cn> wrote:

>
> v1 - > v2:
>
> 1. When the macro __loongarch_lp64 is defined, the VTV_PAGE_SIZE is set to
> 64K.
> 2. In the vtv_malloc.cc file __vtv_malloc_init function, it does not check
>    whether VTV_PAGE_SIZE is equal to the system page size, if the macro
>    __loongarch_lp64 is defined.
>
> All regression tests of libvtv passed.
>
>                 === libvtv Summary ===
>
> # of expected passes            176
>
> But I haven't tested the performance yet.
>
> -----------------------------------
> Co-Authored-By: qijingwen <qijingwen@loongson.cn>
>
> include/ChangeLog:
>
>         * vtv-change-permission.h (defined):
>         (VTV_PAGE_SIZE): Under the loongarch64 architecture,
>         set VTV_PAGE_SIZE to 64K.
>
> libvtv/ChangeLog:
>
>         * configure.tgt: Add loongarch support.
>         * vtv_malloc.cc (defined): If macro __loongarch_lp64 is
>         defined, then don't check whether VTV_PAGE_SIZE is the
>         same as the system page size.
> ---
>  include/vtv-change-permission.h | 4 ++++
>  libvtv/configure.tgt            | 3 +++
>  libvtv/vtv_malloc.cc            | 5 +++++
>  3 files changed, 12 insertions(+)
>
> diff --git a/include/vtv-change-permission.h
> b/include/vtv-change-permission.h
> index 70bdad92bca..64e419c29d5 100644
> --- a/include/vtv-change-permission.h
> +++ b/include/vtv-change-permission.h
> @@ -48,6 +48,10 @@ extern void __VLTChangePermission (int);
>  #else
>  #if defined(__sun__) && defined(__svr4__) && defined(__sparc__)
>  #define VTV_PAGE_SIZE 8192
> +/* LoongArch architecture 64-bit system supports 4k,16k and 64k
> +   page size, which is set to the maximum value here.  */
> +#elif defined(__loongarch_lp64)
> +#define VTV_PAGE_SIZE 65536
>  #else
>  #define VTV_PAGE_SIZE 4096
>  #endif
> diff --git a/libvtv/configure.tgt b/libvtv/configure.tgt
> index aa2a3f675b8..6cdd1e97ab1 100644
> --- a/libvtv/configure.tgt
> +++ b/libvtv/configure.tgt
> @@ -50,6 +50,9 @@ case "${target}" in
>         ;;
>    x86_64-*-darwin[1]* | i?86-*-darwin[1]*)
>         ;;
> +  loongarch*-*-linux*)
> +       VTV_SUPPORTED=yes
> +       ;;
>    *)
>         ;;
>  esac
> diff --git a/libvtv/vtv_malloc.cc b/libvtv/vtv_malloc.cc
> index 67c5de6d4e9..45804b8d7f8 100644
> --- a/libvtv/vtv_malloc.cc
> +++ b/libvtv/vtv_malloc.cc
> @@ -212,6 +212,11 @@ __vtv_malloc_init (void)
>
>  #if defined (__CYGWIN__) || defined (__MINGW32__)
>    if (VTV_PAGE_SIZE != sysconf_SC_PAGE_SIZE())
> +#elif defined (__loongarch_lp64)
> +  /* I think that under the LoongArch 64-bit system, VTV_PAGE_SIZE is set
> +     to the maximum value of 64K supported by the system, so there is no
> +     need to judge here.  */
> +  if (false)
>  #else
>    if (VTV_PAGE_SIZE != sysconf (_SC_PAGE_SIZE))
>

Is "if (VTV_PAGE_SIZE != sysconf (_SC_PAGE_SIZE))" going to fail for
loongarch?  If not, why do you need to insert anything here at all?  If so,
perhaps you could write something similar to sysconf_SC_PAGE_SIZE for
loongarch (as was done for __CYGWIN__ & __MINGW32__)?

-- Caroline
cmtice@google.com



>  #endif
> --
> 2.31.1
>
>