| Message ID | 20200226181020.19592-4-alex.bennee@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix codegen translation cache size | expand |
On 2/26/20 10:10 AM, Alex Bennée wrote: > There is no particular reason to use a static codegen buffer on 64 bit > hosts as we have address space to burn. Allow the common CONFIG_USER > case to use the mmap'ed buffers like SoftMMU. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > accel/tcg/translate-all.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
On 2/26/20 7:10 PM, Alex Bennée wrote: > There is no particular reason to use a static codegen buffer on 64 bit > hosts as we have address space to burn. Allow the common CONFIG_USER > case to use the mmap'ed buffers like SoftMMU. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > accel/tcg/translate-all.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index 5b66af783b5..4ce5d1b3931 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -892,11 +892,12 @@ static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1, > } > } > > -#if defined(CONFIG_USER_ONLY) > -/* Currently it is not recommended to allocate big chunks of data in > - user mode. It will change when a dedicated libc will be used. */ > -/* ??? 64-bit hosts ought to have no problem mmaping data outside the > - region in which the guest needs to run. Revisit this. */ > +#if defined(CONFIG_USER_ONLY) && TCG_TARGET_REG_BITS == 32 > +/* > + * For user mode on smaller 32 bit systems we may run into trouble > + * allocating big chunks of data in the right place. On these systems > + * we utilise a static code generation buffer directly in the binary. > + */ > #define USE_STATIC_CODE_GEN_BUFFER > #endif > > Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
On Wed, Feb 26, 2020 at 7:12 PM Alex Bennée <alex.bennee@linaro.org> wrote: > There is no particular reason to use a static codegen buffer on 64 bit > hosts as we have address space to burn. Allow the common CONFIG_USER > case to use the mmap'ed buffers like SoftMMU. > > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > --- > accel/tcg/translate-all.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c > index 5b66af783b5..4ce5d1b3931 100644 > --- a/accel/tcg/translate-all.c > +++ b/accel/tcg/translate-all.c > @@ -892,11 +892,12 @@ static void page_lock_pair(PageDesc **ret_p1, > tb_page_addr_t phys1, > } > } > > -#if defined(CONFIG_USER_ONLY) > -/* Currently it is not recommended to allocate big chunks of data in > - user mode. It will change when a dedicated libc will be used. */ > -/* ??? 64-bit hosts ought to have no problem mmaping data outside the > - region in which the guest needs to run. Revisit this. */ > +#if defined(CONFIG_USER_ONLY) && TCG_TARGET_REG_BITS == 32 > +/* > + * For user mode on smaller 32 bit systems we may run into trouble > + * allocating big chunks of data in the right place. On these systems > + * we utilise a static code generation buffer directly in the binary. > + */ > #define USE_STATIC_CODE_GEN_BUFFER > #endif > > -- > 2.20.1 > > > Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com> -- Niek Linnenbank <div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Feb 26, 2020 at 7:12 PM Alex Bennée <<a href="mailto:alex.bennee@linaro.org">alex.bennee@linaro.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">There is no particular reason to use a static codegen buffer on 64 bit<br> hosts as we have address space to burn. Allow the common CONFIG_USER<br> case to use the mmap'ed buffers like SoftMMU.<br> <br> Signed-off-by: Alex Bennée <<a href="mailto:alex.bennee@linaro.org" target="_blank">alex.bennee@linaro.org</a>><br> ---<br> accel/tcg/translate-all.c | 11 ++++++-----<br> 1 file changed, 6 insertions(+), 5 deletions(-)<br> <br> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c<br> index 5b66af783b5..4ce5d1b3931 100644<br> --- a/accel/tcg/translate-all.c<br> +++ b/accel/tcg/translate-all.c<br> @@ -892,11 +892,12 @@ static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1,<br> }<br> }<br> <br> -#if defined(CONFIG_USER_ONLY)<br> -/* Currently it is not recommended to allocate big chunks of data in<br> - user mode. It will change when a dedicated libc will be used. */<br> -/* ??? 64-bit hosts ought to have no problem mmaping data outside the<br> - region in which the guest needs to run. Revisit this. */<br> +#if defined(CONFIG_USER_ONLY) && TCG_TARGET_REG_BITS == 32<br> +/*<br> + * For user mode on smaller 32 bit systems we may run into trouble<br> + * allocating big chunks of data in the right place. On these systems<br> + * we utilise a static code generation buffer directly in the binary.<br> + */<br> #define USE_STATIC_CODE_GEN_BUFFER<br> #endif<br> <br> -- <br> 2.20.1<br> <br> <br> </blockquote></div>Reviewed-by: Niek Linnenbank <<a href="mailto:nieklinnenbank@gmail.com">nieklinnenbank@gmail.com</a>><br clear="all"><div><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div>Niek Linnenbank<br><br></div></div></div></div></div>
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 5b66af783b5..4ce5d1b3931 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -892,11 +892,12 @@ static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1, } } -#if defined(CONFIG_USER_ONLY) -/* Currently it is not recommended to allocate big chunks of data in - user mode. It will change when a dedicated libc will be used. */ -/* ??? 64-bit hosts ought to have no problem mmaping data outside the - region in which the guest needs to run. Revisit this. */ +#if defined(CONFIG_USER_ONLY) && TCG_TARGET_REG_BITS == 32 +/* + * For user mode on smaller 32 bit systems we may run into trouble + * allocating big chunks of data in the right place. On these systems + * we utilise a static code generation buffer directly in the binary. + */ #define USE_STATIC_CODE_GEN_BUFFER #endif
There is no particular reason to use a static codegen buffer on 64 bit hosts as we have address space to burn. Allow the common CONFIG_USER case to use the mmap'ed buffers like SoftMMU. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- accel/tcg/translate-all.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) -- 2.20.1