Messages in this thread | | | Subject | Re: [PATCH 1/2] x86 boot: add E820_RESVD_KERN | From | "Huang, Ying" <> | Date | Mon, 30 Jun 2008 15:51:43 +0800 |
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On Mon, 2008-06-30 at 00:34 -0700, Yinghai Lu wrote: > On Mon, Jun 30, 2008 at 12:03 AM, Huang, Ying <ying.huang@intel.com> wrote: > > On Fri, 2008-06-27 at 15:05 -0700, Yinghai Lu wrote: > >> On Thu, Jun 26, 2008 at 7:48 PM, Huang, Ying <ying.huang@intel.com> wrote: > >> > On Thu, 2008-06-26 at 19:22 -0700, Yinghai Lu wrote: > >> >> On Thu, Jun 26, 2008 at 2:47 AM, Yinghai Lu <yhlu.kernel@gmail.com> wrote: > >> >> > On Thu, Jun 26, 2008 at 12:48 AM, Huang, Ying <ying.huang@intel.com> wrote: > >> >> >> On Thu, 2008-06-26 at 00:25 -0700, Yinghai Lu wrote: > >> >> >> [...] > >> >> >>> > if (pfn >= limit_pfn) > >> >> >>> > @@ -977,7 +978,7 @@ u64 __init early_reserve_e820(u64 startt > >> >> >>> > return 0; > >> >> >>> > > >> >> >>> > addr = round_down(start + size - sizet, align); > >> >> >>> > - e820_update_range(addr, sizet, E820_RAM, E820_RESERVED); > >> >> >>> > + e820_update_range(addr, sizet, E820_RAM, E820_RESVD_KERN); > >> >> >>> > >> >> >>> this line is not needed. > >> >> >> > >> >> >> Why? Memory reserved by early_rserved_e820 should not be saved during > >> >> >> hibernation? shoudl not be saved by kdump? > >> >> >> > >> > > >> > Can you tell me why this line is not needed? > >> > > >> > [...] > >> >> some like the attach patch... > >> >> > >> >> you still can merge parse_setup_data parse_e820_ext > >> >> also entries in parse_e820_ext is not initialized..., __copy_e820_map > >> >> will do nothing. > >> > > >> > OK. Because some E820 entries are available after parse_setup_data(), > >> > it is better to call reserve_setup_data() after calling > >> > parse_setup_data() if update_e820_range() is used instead of > >> > reserve_early(). > >> > >> please modify it and test on your platforms then submit to Ingo.. > > > > It seems that there is an issue: > > > > - If parse_setup_data() is called before reserve_setup_data(), and there > > is a conflict between memory area used by setup_data and other memory > > area, it is possible that the contents of setup_data is changed. So that > > system may panic before reporting memory area conflict. And it seems > > that memory area conflict is not checked by e820_update_range(). > > what is "other memory area"? returned from find_e820_area? no one use that yet.
I mean memory area reserved with reserved_early() or e820_update_range() before reserve_setup_data() is called.
And because there is no conflict check in e820_update_range(), what to deal with potential conflict between setup_data and other memory area regardless which one is reserved earlier?
Another issue related:
Because some memmap entries are available via extended E820 memmap (SETUP_E820_EXT), it is not strictly safe to use e820_update_range() between setup_memory_map() and parse_setup_data(). It may be better to parse extended E820 memmap right after setup_memory_map().
Best Regards, Huang Ying -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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