On 05/11/22 at 05:50pm, Leizhen (ThunderTown) wrote:
>
>
> On 2022/5/11 17:06, Baoquan He wrote:
> > On 05/11/22 at 11:20am, Zhen Lei wrote:
> >> When "crashkernel=X,high" is specified, the specified "crashkernel=Y,low"
> >> memory is not required in the following corner cases:
> >> 1. If both CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, it means
> >> that the devices can access any memory.
> >> 2. If the system memory is small, the crash high memory may be allocated
> >> from the DMA zones. If that happens, there's no need to allocate
> >> another crash low memory because there's already one.
> >>
> >> Add condition '(crash_base >= CRASH_ADDR_LOW_MAX)' to determine whether
> >> the 'high' memory is allocated above DMA zones. Note: when both
> >> CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, the entire physical
> >> memory is DMA accessible, CRASH_ADDR_LOW_MAX equals 'PHYS_MASK + 1'.
> >>
> >> Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
> >> ---
> >> Documentation/admin-guide/kernel-parameters.txt | 5 +++--
> >> arch/arm64/mm/init.c | 3 ++-
> >> 2 files changed, 5 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> >> index f6ff55840751a78..1b543c3109f4851 100644
> >> --- a/Documentation/admin-guide/kernel-parameters.txt
> >> +++ b/Documentation/admin-guide/kernel-parameters.txt
> >> @@ -823,7 +823,7 @@
> >> low memory is needed to make sure DMA buffers for 32-bit
> >> devices won't run out. Kernel would try to allocate
> >> at least 256M below 4G automatically.
> >> - This one let user to specify own low range under 4G
> >> + This one lets the user specify own low range under 4G
> > ~ This one let users specify own low range ...
> >
> > Other than this nitpick, LGTM
>
> This is Catalin's response a few days ago:
> Slightly more correct is "This one lets the user specify..."
>
> I didn't googled "This one lets", but I googled "It lets". I think he wrote it right.
>
> Both "the user" and "users" seem to be right.
Yeah, I forgot the 'this one lets' part, and I am fine too with the 'the
use'if it's right. So please ignore the comment.
>
>
> >
> > Acked-by: Baoquan He <bhe@xxxxxxxxxx>
> >
> >> for second kernel instead.
> >> 0: to disable low allocation.
> >> It will be ignored when crashkernel=X,high is not used
> >> @@ -832,7 +832,8 @@
> >> [KNL, ARM64] range in low memory.
> >> This one lets the user specify a low range in the
> >> DMA zone for the crash dump kernel.
> >> - It will be ignored when crashkernel=X,high is not used.
> >> + It will be ignored when crashkernel=X,high is not used
> >> + or memory reserved is located in the DMA zones.
> >>
> >> cryptomgr.notests
> >> [KNL] Disable crypto self-tests
> >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> >> index 18ba66c90991ea0..ac510fb6a2c0189 100644
> >> --- a/arch/arm64/mm/init.c
> >> +++ b/arch/arm64/mm/init.c
> >> @@ -170,7 +170,8 @@ static void __init reserve_crashkernel(void)
> >> return;
> >> }
> >>
> >> - if (crash_low_size && reserve_crashkernel_low(crash_low_size)) {
> >> + if ((crash_base >= CRASH_ADDR_LOW_MAX) &&
> >> + crash_low_size && reserve_crashkernel_low(crash_low_size)) {
> >> memblock_phys_free(crash_base, crash_size);
> >> return;
> >> }
> >> --
> >> 2.25.1
> >>
> >
> > .
> >
>
> --
> Regards,
> Zhen Lei
>
