On 08/16/2013 04:28 AM, Yinghai Lu wrote:
......
So, we still need reordering, and put a new requirement that all earlier
allocations must be small...
I think the root of this issue is that ACPI init point is not early
enough in the boot sequence. If it were much earlier already, the whole
thing would have been very simple. We are now trying to workaround this
issue in the mblock code (which itself is a fine idea), but this ACPI
issue still remains and similar issues may come up again in future.
For instance, ACPI SCPR/DBGP/DBG2 tables allow the OS to initialize
serial console/debug ports at early boot time. The earlier it can be
initialized, the better this feature will be. These tables are not
currently used by Linux due to a licensing issue, but it could be
addressed some time soon. As platforms becoming more complex& legacy
free, the needs of ACPI tables will increase.
I think moving up the ACPI init point earlier is a good direction.
Good point.
If we put acpi_initrd_override in BRK, and can more acpi_boot_table_init()
much early.
Hi yinghai, toshi,
Since I brought up this issue, it has been a long time. And there were a
lot
of different solutions came up. No solution is perfect enough for everyone.
I have tried a lot, and most of them failed. But I think most of the things
cannot be seen clearly without a real patch posted. Many good ideas came up
during patch reviewing.
So I think I'm going to try as many ways as possible. :)
Parsing SRAT earlier is what I want to do in the very beginning indeed. And
now, seems that moving the whole acpi table installation and overriding
earlier
will bring us much more benefits. I have tried this without moving up
acpi_initrd_override in my part1 patch-set. But not in the way Yinghai
mentioned
above.
Seeing from the code, there are 5 pages in BRK for page tables.
81 /* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */
82 #define INIT_PGT_BUF_SIZE (5 * PAGE_SIZE)
83 RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE);
By "put acpi_initrd_override in BRK", do you mean increase the BRK by
default ?
Thanks.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>