On 3/23/23 06:24, Wu, Fei wrote:
There is MSTATUS_MPRV and MSTATUS_MPP kind of thing, priv+sum is not
able to represent all of the status, probably we can just add an extra
'priv' at the back of TB_FLAGS?
MPRV+MPP looks not necessary be in TB_FLAGS, it's just used to calculate
the mmu_idx. Is
On 3/22/23 17:38, Wu, Fei wrote:
There is MSTATUS_MPRV and MSTATUS_MPP kind of thing, priv+sum is not
able to represent all of the status, probably we can just add an extra
'priv' at the back of TB_FLAGS?
Yes, I think that's required.
r~
On 3/23/2023 8:38 AM, Wu, Fei wrote:
> On 3/22/2023 9:19 PM, Richard Henderson wrote:
>> On 3/22/23 05:12, Fei Wu wrote:
>>> Kernel needs to access user mode memory e.g. during syscalls, the window
>>> is usually opened up for a very limited time through MSTATUS.SUM, the
>>> overhead is too much
On 3/23/2023 8:38 AM, Wu, Fei wrote:
> On 3/22/2023 9:19 PM, Richard Henderson wrote:
>> On 3/22/23 05:12, Fei Wu wrote:
>>> Kernel needs to access user mode memory e.g. during syscalls, the window
>>> is usually opened up for a very limited time through MSTATUS.SUM, the
>>> overhead is too much
On 3/22/2023 9:19 PM, Richard Henderson wrote:
> On 3/22/23 05:12, Fei Wu wrote:
>> Kernel needs to access user mode memory e.g. during syscalls, the window
>> is usually opened up for a very limited time through MSTATUS.SUM, the
>> overhead is too much if tlb_flush() gets called for every SUM
On 3/22/23 05:12, Fei Wu wrote:
Kernel needs to access user mode memory e.g. during syscalls, the window
is usually opened up for a very limited time through MSTATUS.SUM, the
overhead is too much if tlb_flush() gets called for every SUM change.
This patch creates a separate MMU index for S+SUM,
On 3/22/2023 8:37 PM, liweiwei wrote:
>
> On 2023/3/22 20:12, Fei Wu wrote:
>> Kernel needs to access user mode memory e.g. during syscalls, the window
>> is usually opened up for a very limited time through MSTATUS.SUM, the
>> overhead is too much if tlb_flush() gets called for every SUM change.
On 2023/3/22 20:12, Fei Wu wrote:
Kernel needs to access user mode memory e.g. during syscalls, the window
is usually opened up for a very limited time through MSTATUS.SUM, the
overhead is too much if tlb_flush() gets called for every SUM change.
This patch creates a separate MMU index for
Kernel needs to access user mode memory e.g. during syscalls, the window
is usually opened up for a very limited time through MSTATUS.SUM, the
overhead is too much if tlb_flush() gets called for every SUM change.
This patch creates a separate MMU index for S+SUM, so that it's not
necessary to
