Le ven. 14 juil. 2023, 05:25, Cyan via Grub-devel <grub-devel@gnu.org> a écrit :
> Hi Daniel, > > On 7/14/23 02:38, Daniel Kiper wrote: > > On Tue, Jul 11, 2023 at 09:37:15PM +0800, Cyan Yang via Grub-devel wrote: > > > > You are mixing enum and int types. The function should return 0 here. > > > > Yes, the hook function should return zero instead of enum vaule > GRUB_ERR_NONE. > > > > Anyway, I think it would be nice if you could upstream this module. > > Potentially other people may find it useful. > > > > Thanks for the suggestion, and yes I was planning to upstream this > module. However, a serious issue have been discovered during the initial > test, made me concerning that this way of presenting the amount of > physical memory should not be considered as the primary way: > > When running on a VM it did not report the real amount of system memory. > A few hundred KiB of memory was left undetected, probably reserved by > firmware or hardware. > > Here's an example, on a Virtualbox VM: > > grub> phymem > The total system memory is 8191 MiB (8589539328 bytes). > > while allocated RAM for the VM is 8192MiB (8589934592 Bytes). > > Users usually expect the real amount, which should be a multiple of e.g. > 2MiB or even bigger. My code[1] is currently rounding the result to the > closest multiple of 2MiB or 128MiB, which depends on platform. The > number is totally an assumption, and there's a chance that some systems > can reserve more than that. > > So basically there are two options: > > 1. We detect the amount of system memory by traversing the GRUB memory > map, return it as is, do not process the result. Downside of this is, > that users who write scripts should pay attention to the possible > "cutout", to avoid using a multiple of 1MiB while doing comparisons: > > # This should be avoided if we choose the first option > if [ $total_mem -lt 8192 ] ; then > > 2. Provide a more accurate way of detecting the amount of physical > memory. Downside of this is there will be more code to write, and more > lot more work to do, as the detection logic probably is platform dependent. > Just add an option to consider "reserved" memory as available. User's choice. Fire you it's a single if. > > Thanks, > Cinhi > > [1]: https://github.com/AOSC-Dev/grub/tree/grub-2.06-aosc > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel >
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