* Re: Re: [PATCH] BadRAM for 2.5.73-mm2
@ 2003-07-02 12:58 steven.newbury1
0 siblings, 0 replies; only message in thread
From: steven.newbury1 @ 2003-07-02 12:58 UTC (permalink / raw)
To: Oleg Drokin; +Cc: linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2467 bytes --]
============================================================
From: Oleg Drokin <green@namesys.com>
Date: 2003/07/02 Wed AM 06:23:24 GMT
To: steven.newbury1@ntlworld.com
CC: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] BadRAM for 2.5.73-mm2
Hello!
On Wed, Jul 02, 2003 at 03:33:26AM +0000, steven.newbury1@ntlworld.com wrote:
> It will probably apply cleanly to 2.5.73 as well but I haven't checked it
> yet...
This
> It is based it on
> http://rick.vanrein.org/linux/badram/software/BadRAM-2.4.20.1.patch
and this patches both have a bug that effectively disables all highmem (if present)
when badram patch is activated. I contacted Rick, but never got any answer back.
(in fact I got an auto reply from some Debian bugtracking system, but that's about it).
Corrected 2.4.21 version of the patch is available at
http://linuxhacker.ru/patches/2.4.21-badram.diff
The arch/i386/mm/init.c part:
> +void __init one_highpage_init(struct page *page, int pfn, int bad_ppro,
> + _Bool *bad)
> {
> + *bad = 0;
> if (page_is_ram(pfn) && !(bad_ppro && page_kills_ppro(pfn))) {
> ClearPageReserved(page);
> set_bit(PG_highmem, &page->flags);
> set_page_count(page, 1);
> - __free_page(page);
> +#ifdef CONFIG_BADRAM
> + if (PageBad(page))
> + *bad = 1;
> + else
> +#else
> + __free_page(page);
> +#endif
> totalhigh_pages++;
should obviously get "#else" replaced with "#endif" and original "#endif" should be removed
because otherwise all of the highmem pages are either bad or used right from the initialisation.
(Yes, I have highmem (2G RAM) system with 2 bits bad and I am too lazy to to go to the store to
replace the RAM modules, so I given a patch a try and discovered this problem (which is there
for a long time it seems). I suspect that I am the only one who runs this patch on highmem system,
though ;) )
Bye,
Oleg
============================================================
Thanks Oleg!
Strangely enough I had this right but then "fixed" it. I obviously had to manually apply the patch to arch/i386/mm/init.c since there are a few logic changes etc. I only re-inserted the bug when checking the changes I had made compared to the original patch and assumed that I had been wrong (I assumed the original patch worked ;-)).
Attached is the new patch.
[-- Attachment #2: BadRAM-2.5.73-mm2.1.diff --]
[-- Type: application/octet-stream, Size: 23991 bytes --]
diff -urN linux-2.5.73-mm2/CREDITS linux-2.5/CREDITS
--- linux-2.5.73-mm2/CREDITS 2003-06-17 05:20:07.000000000 +0100
+++ linux-2.5/CREDITS 2003-07-02 01:58:52.000000000 +0100
@@ -2365,6 +2365,12 @@
S: 55127 Mainz
S: Germany
+N: Steven Newbury
+E: s_j_newbury@yahoo.co.uk
+D: Forward ported BadRAM patch to 2.5.73 from 2.4.20
+S: Derby
+S: United Kingdom
+
N: David C. Niemi
E: niemi@tux.org
W: http://www.tux.org/~niemi/
@@ -2601,6 +2607,14 @@
S: Malvern, Pennsylvania 19355
S: USA
+N: Rick van Rein
+E: vanrein@cs.utwente.nl
+W: http://www.cs.utwente.nl/~vanrein
+D: Memory, the BadRAM subsystem dealing with statically challanged RAM modules.
+S: Binnenes 67
+S: 9407 CX Assen
+S: The Netherlands
+
N: Stefan Reinauer
E: stepan@linux.de
W: http://www.freiburg.linux.de/~stepan/
@@ -2819,6 +2833,13 @@
E:
D: Macintosh IDE Driver
+N: Nico Schmoigl
+E: nico@writemail.com
+W: http://webrum.uni-mannheim.de/math/schmoigl/linux/
+D: Migration of BadRAM patch to 2.4.4 series (with Rick van Rein)
+S: Mannheim, BW, Germany
+P: 2047/38FC9E03 5D DB 09 E4 3F F3 CD 09 75 59 - 11 17 9C 03 46 E3 38 FC 9E 03
+
N: Peter De Schrijver
E: stud11@cc4.kuleuven.ac.be
D: Mitsumi CD-ROM driver patches March version
diff -urN linux-2.5.73-mm2/Documentation/badram.txt linux-2.5/Documentation/badram.txt
--- linux-2.5.73-mm2/Documentation/badram.txt 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.5/Documentation/badram.txt 2003-07-01 20:02:27.000000000 +0100
@@ -0,0 +1,266 @@
+INFORMATION ON USING BAD RAM MODULES
+====================================
+
+Introduction
+ RAM is getting smaller and smaller, and as a result, also more and more
+ vulnerable. This makes the manufacturing of hardware more expensive,
+ since an excessive amount of RAM chips must be discarded on account of
+ a single cell that is wrong. Similarly, static discharge may damage a
+ RAM module forever, which is usually remedied by replacing it
+ entirely.
+
+ This is not necessary, as the BadRAM code shows: By informing the Linux
+ kernel which addresses in a RAM are damaged, the kernel simply avoids
+ ever allocating such addresses but makes all the rest available.
+
+Reasons for this feature
+ There are many reasons why this kernel feature is useful:
+ - Chip manufacture is resource intensive; waste less and sleep better
+ - It's another chance to promote Linux as "the flexible OS"
+ - Some laptops have their RAM soldered in... and then it fails!
+ - It's plain cool ;-)
+
+Running example
+ To run this project, I was given two DIMMs, 32 MB each. One, that we
+ shall use as a running example in this text, contained 512 faulty bits,
+ spread over 1/4 of the address range in a regular pattern. Some tricks
+ with a RAM tester and a few binary calculations were sufficient to
+ write these faults down in 2 longword numbers.
+
+ The kernel recognised the correct number of pages with faults and did
+ not give them out for allocation. The allocation routines could
+ therefore progress as normally, without any adaption.
+ So, I gained 30 MB of DIMM which would otherwise have been thrown
+ away. After booting the kernel, the kernel behaved exactly as it
+ always had.
+
+Initial checks
+ If you experience RAM trouble, first read /usr/src/linux/memory.txt
+ and try out the mem=4M trick to see if at least some initial parts
+ of your RAM work well. The BadRAM routines halt the kernel in panic
+ if the reserved area of memory (containing kernel stuff) contains
+ a faulty address.
+
+Running a RAM checker
+ The memory checker is not built into the kernel, to avoid delays at
+ runtime. If you experience problems that may be caused by RAM, run
+ a good RAM checker, such as
+ http://reality.sgi.com/cbrady_denver/memtest86
+ The output of a RAM checker provides addresses that went wrong. In
+ the 32 MB chip with 512 faulty bits mentioned above, the errors were
+ found in the 8MB-16MB range (the DIMM was in slot #0) at addresses
+ xxx42f4
+ xxx62f4
+ xxxc2f4
+ xxxe2f4
+ and the error was a "sticky 1 bit", a memory bit that stayed "1" no
+ matter what was written to it. The regularity of this pattern
+ suggests the death of a buffer at the output stages of a row on one of
+ the chips. I expect such regularity to be commonplace. Finding this
+ regularity currently is human effort, but it should not be hard to
+ alter a RAM checker to capture it in some sort of pattern, possibly
+ the BadRAM patterns described below.
+
+ By the way, if you manage to get hold of memtest86 version 2.3 or
+ beyond, you can configure the printing mode to produce BadRAM patterns,
+ which find out exactly what you must enter on the LILO: commandline,
+ except that you shouldn't mention the added spacing. That means that
+ you can skip the following step, which saves you a *lot* of work.
+
+ Also by the way, if your machine has the ISA memory gap in the 15M-16M
+ range unstoppable, Linux can get in trouble. One way of handling that
+ situation is by specifying the total memory size to Linux with a boot
+ parameter mem=... and then to tell it to treat the 15M-16M range as
+ faulty with an additional boot parameter, for instance:
+ mem=24M badram=0x00f00000,0xfff00000
+ if you installed 24MB of RAM in total.
+
+Capturing errors in a pattern
+ Instead of manually providing all 512 errors to the kernel, it's nicer
+ to generate a pattern. Since the regularity is based on address decoding
+ software, which generally takes certain bits into account and ignores
+ others, we shall provide a faulty address F, together with a bit mask M
+ that specifies which bits must be equal to F. In C code, an address A
+ is faulty if and only if
+ (F & M) == (A & M)
+ or alternately (closer to a hardware implementation):
+ ~((F ^ A) & M)
+ In the example 32 MB chip, we had the faulty addresses in 8MB-16MB:
+ xxx42f4 ....0100....
+ xxx62f4 ....0110....
+ xxxc2f4 ....1100....
+ xxxe2f4 ....1110....
+ The second column represents the alternating hex digit in binary form.
+ Apperantly, the first and one-but last binary digit can be anything,
+ so the binary mask for that part is 0101. The mask for the part after
+ this is 0xfff, and the part before should select anything in the range
+ 8MB-16MB, or 0x00800000-0x01000000; this is done with a bitmask
+ 0xff80xxxx. Combining these partial masks, we get:
+ F=0x008042f4 M=0xff805fff
+ That covers everything for this DIMM; for more complicated failing
+ DIMMs, or for a combination of multiple failing DIMMs, it can be
+ necessary to set up a number of such F/M pairs.
+
+Rebooting Linux
+ Now that these patterns are known (and double-checked, the calculations
+ are highly error-prone... it would be neat to test them in the RAM
+ checker...) we simply restart Linux with these F/M pairs as a parameter.
+ If you normally boot as follows:
+ LILO: linux
+ you should now boot with
+ LILO: linux badram=0x008042f4,0xff805fff
+ or perhaps by mentioning more F/M pairs in an order F0,M0,F1,M1,...
+ When you provide an odd number of arguments to badram, the default mask
+ 0xffffffff (only one address matched) is applied to the pattern.
+
+ Beware of the commandline length. At least up to LILO version 0.21,
+ the commandline is cut off after the 78th character; later versions
+ may go as far as the kernel goes, namely 255 characters. In no way is
+ it possible to enter more than 10 numbers to the badram boot option.
+
+ When the kernel now boots, it should not give any trouble with RAM.
+ Mind you, this is under the assumption that the kernel and its data
+ storage do not overlap an erroneous part. If this happens, and the
+ kernel does not choke on it right away, it will stop with a panic.
+ You will need to provide a RAM where the initial, say 2MB, is faultless.
+
+ Now look up your memory status with
+ dmesg | grep ^Memory:
+ which prints a single line with information like
+ Memory: 158524k/163840k available
+ (940k kernel code,
+ 412k reserved,
+ 1856k data,
+ 60k init,
+ 0k highmem,
+ 2048k BadRAM)
+ The latter entry, the badram, is 2048k to represent the loss of 2MB
+ of general purpose RAM due to the errors. Or, positively rephrased,
+ instead of throwing out 32MB as useless, you only throw out 2MB.
+
+ If the system is stable (try compiling a few kernels, and do a few
+ finds in / or so) you may add the boot parameter to /etc/lilo.conf
+ as a line to _all_ the kernels that handle this trouble with a line
+ append="badram=0x008042f4,0xff805fff"
+ after which you run "lilo".
+ Warning: Don't experiment with these settings on your only boot image.
+ If the BadRAM overlays kernel code, data, init, or other reserved
+ memory, the kernel will halt in panic. Try settings on a test boot
+ image first, and if you get a panic you should change the order of
+ your DIMMs [which may involve buying a new one just to be able to
+ change the order].
+
+ You are allowed to enter any number of BadRAM patterns in all the
+ places documented in this file. They will all apply. It is even
+ possible to mention several BadRAM patterns in a single place. The
+ completion of an odd number of arguments with the default mask is
+ done separately for each badram=... option.
+
+Kernel Customisation
+ Some people prefer to enter their badram patterns in the kernel, and
+ this is also possible. In mm/page_alloc.c there is an array of unsigned
+ long integers into which the parameters can be entered, prefixed with
+ the number of integers (twice the number of patterns). The array is
+ named badram_custom and it will be added to the BadRAM list whenever an
+ option 'badram' is provided on the commandline when booting, ealancing, Kanoj Sarcar, SGI, Jan 2000
* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ * BadRAM handling, Rick van Rein, Feb 2001
*/
#include <linux/config.h>
@@ -1615,3 +1616,96 @@
setup_per_zone_pages_min();
return 0;
}
+
+
+#ifdef CONFIG_BADRAM
+
+/* Given a pointed-at address and a mask, increment the page so that the
+ * mask hides the increment. Return 0 if no increment is possible.
+ */
+static int __init next_masked_address (unsigned long *addrp, unsigned long mask)
+{
+ unsigned long inc=1;
+ unsigned long newval = *addrp;
+ while (inc & mask)
+ inc += inc;
+ while (inc != 0) {
+ newval += inc;
+ newval &= ~mask;
+ newval |= ((*addrp) & mask);
+ if (newval > *addrp) {
+ *addrp = newval;
+ return 1;
+ }
+ do {
+ inc += inc;
+ } while (inc & ~mask);
+ while (inc & mask)
+ inc += inc;
+ }
+ return 0;
+}
+
+
+void __init badram_markpages (int argc, unsigned long *argv) {
+ unsigned long addr, mask;
+ while (argc-- > 0) {
+ addr = *argv++;
+ mask pro;
@@ -467,13 +479,17 @@
totalram_pages += __free_all_bootmem();
reservedpages = 0;
+ badpages = 0;
for (tmp = 0; tmp < max_low_pfn; tmp++)
/*
- * Only count reserved RAM pages
+ * Only count reserved and bad RAM pages
*/
+ Note that this scheme has delibpfn) ((pfn) < max_mapnr)
#endif /* !CONFIG_DISCONTIGMEM */
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define phys_to_page(x) (mem_map + ((unsigned long)(x) >> PAGE_SHIFT))
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff -urN linux-2.5.73-mm2/mm/bootmem.c linux-2.5/mm/bootmem.c
--- linux-2.5.73-mm2/mm/bootmem.c 2003-06-17 05:19:47.000000000 +0100
+++ linux-2.5/mm/bootmem.c 2003-07-01 20:42:25.000000000 +0100
@@ -274,8 +274,17 @@
if (v & m) {
count++;
ClearPageReserved(page);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+
set_page_count(page, 1);
__free_page(page);
+#endif
}
}
} else {
@@ -294,8 +303,16 @@
for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
count++;
ClearPageReserved(page);
- set_page_count(page, 1);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+ set_page_count(page, 1);
__free_page(page);
+#endif
}
total += count;
bdata->node_bootmem_map = NULL;
diff -urN linux-2.5.73-mm2/mm/page_alloc.c linux-2.5/mm/page_alloc.c
--- linux-2.5.73-mm2/mm/page_alloc.c 2003-07-01 19:59:57.000000000 +0100
+++ linux-2.5/mm/page_alloc.c 2003-07-02 01:12:09.000000000 + a preference for BadRAM pages, anpfn) ((pfn) < max_mapnr)
#endif /* !CONFIG_DISCONTIGMEM */
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define phys_to_page(x) (mem_map + ((unsigned long)(x) >> PAGE_SHIFT))
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff -urN linux-2.5.73-mm2/mm/bootmem.c linux-2.5/mm/bootmem.c
--- linux-2.5.73-mm2/mm/bootmem.c 2003-06-17 05:19:47.000000000 +0100
+++ linux-2.5/mm/bootmem.c 2003-07-01 20:42:25.000000000 +0100
@@ -274,8 +274,17 @@
if (v & m) {
count++;
ClearPageReserved(page);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+
set_page_count(page, 1);
__free_page(page);
+#endif
}
}
} else {
@@ -294,8 +303,16 @@
for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
count++;
ClearPageReserved(page);
- set_page_count(page, 1);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+ set_page_count(page, 1);
__free_page(page);
+#endif
}
total += count;
bdata->node_bootmem_map = NULL;
diff -urN linux-2.5.73-mm2/mm/page_alloc.c linux-2.5/mm/page_alloc.c
--- linux-2.5.73-mm2/mm/page_alloc.c 2003-07-01 19:59:57.000000000 +0100
+++ linux-2.5/mm/page_alloc.c 2003-07-02 01:12:09.000000000 +ject is an idea and implementationpfn) ((pfn) < max_mapnr)
#endif /* !CONFIG_DISCONTIGMEM */
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define phys_to_page(x) (mem_map + ((unsigned long)(x) >> PAGE_SHIFT))
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff -urN linux-2.5.73-mm2/mm/bootmem.c linux-2.5/mm/bootmem.c
--- linux-2.5.73-mm2/mm/bootmem.c 2003-06-17 05:19:47.000000000 +0100
+++ linux-2.5/mm/bootmem.c 2003-07-01 20:42:25.000000000 +0100
@@ -274,8 +274,17 @@
if (v & m) {
count++;
ClearPageReserved(page);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+
set_page_count(page, 1);
__free_page(page);
+#endif
}
}
} else {
@@ -294,8 +303,16 @@
for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
count++;
ClearPageReserved(page);
- set_page_count(page, 1);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+ set_page_count(page, 1);
__free_page(page);
+#endif
}
total += count;
bdata->node_bootmem_map = NULL;
diff -urN linux-2.5.73-mm2/mm/page_alloc.c linux-2.5/mm/page_alloc.c
--- linux-2.5.73-mm2/mm/page_alloc.c 2003-07-01 19:59:57.000000000 +0100
+++ linux-2.5/mm/page_alloc.c 2003-07-02 01:12:09.000000000 +exchanging your
mothealancing, Kanoj Sarcar, SGI, Jan 2000
* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ * BadRAM handling, Rick van Rein, Feb 2001
*/
#include <linux/config.h>
@@ -1615,3 +1616,96 @@
setup_per_zone_pages_min();
return 0;
}
+
+
+#ifdef CONFIG_BADRAM
+
+/* Given a pointed-at address and a mask, increment the page so that the
+ * mask hides the increment. Return 0 if no increment is possible.
+ */
+static int __init next_masked_address (unsigned long *addrp, unsigned long mask)
+{
+ unsigned long inc=1;
+ unsigned long newval = *addrp;
+ while (inc & mask)
+ inc += inc;
+ while (inc != 0) {
+ newval += inc;
+ newval &= ~mask;
+ newval |= ((*addrp) & mask);
+ if (newval > *addrp) {
+ *addrp = newval;
+ return 1;
+ }
+ do {
+ inc += inc;
+ } while (inc & ~mask);
+ while (inc & mask)
+ inc += inc;
+ }
+ return 0;
+}
+
+
+void __init badram_markpages (int argc, unsigned long *argv) {
+ unsigned long addr, mask;
+ while (argc-- > 0) {
+ addr = *argv++;
+ mask pro;
@@ -467,13 +479,17 @@
totalram_pages += __free_all_bootmem();
reservedpages = 0;
+ badpages = 0;
for (tmp = 0; tmp < max_low_pfn; tmp++)
/*
- * Only count reserved RAM pages
+ * Only count reserved and bad RAM pages
*/
0
@@ -223,12 +223,22 @@
pkmap_paalancing, Kanoj Sarcar, SGI, Jan 2000
* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ * BadRAM handling, Rick van Rein, Feb 2001
*/
#include <linux/config.h>
@@ -1615,3 +1616,96 @@
setup_per_zone_pages_min();
return 0;
}
+
+
+#ifdef CONFIG_BADRAM
+
+/* Given a pointed-at address and a mask, increment the page so that the
+ * mask hides the increment. Return 0 if no increment is possible.
+ */
+static int __init next_masked_address (unsigned long *addrp, unsigned long mask)
+{
+ unsigned long inc=1;
+ unsigned long newval = *addrp;
+ while (inc & mask)
+ inc += inc;
+ while (inc != 0) {
+ newval += inc;
+ newval &= ~mask;
+ newval |= ((*addrp) & mask);
+ if (newval > *addrp) {
+ *addrp = newval;
+ return 1;
+ }
+ do {
+ inc += inc;
+ } while (inc & ~mask);
+ while (inc & mask)
+ inc += inc;
+ }
+ return 0;
+}
+
+
+void __init badram_markpages (int argc, unsigned long *argv) {
+ unsigned long addr, mask;
+ while (argc-- > 0) {
+ addr = *argv++;
+ mask pro;
@@ -467,13 +479,17 @@
totalram_pages += __free_all_bootmem();
reservedpages = 0;
+ badpages = 0;
for (tmp = 0; tmp < max_low_pfn; tmp++)
/*
- * Only count reserved RAM pages
+ * Only count reserved and bad RAM pages
*/
if (page_is_ram(tmp) && PageReservpfn) ((pfn) < max_mapnr)
#endif /* !CONFIG_DISCONTIGMEM */
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define phys_to_page(x) (mem_map + ((unsigned long)(x) >> PAGE_SHIFT))
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff -urN linux-2.5.73-mm2/mm/bootmem.c linux-2.5/mm/bootmem.c
--- linux-2.5.73-mm2/mm/bootmem.c 2003-06-17 05:19:47.000000000 +0100
+++ linux-2.5/mm/bootmem.c 2003-07-01 20:42:25.000000000 +0100
@@ -274,8 +274,17 @@
if (v & m) {
count++;
ClearPageReserved(page);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+
set_page_count(page, 1);
__free_page(page);
+#endif
}
}
} else {
@@ -294,8 +303,16 @@
for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
count++;
ClearPageReserved(page);
- set_page_count(page, 1);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+ set_page_count(page, 1);
__free_page(page);
+#endif
}
total += count;
bdata->node_bootmem_map = NULL;
diff -urN linux-2.5.73-mm2/mm/page_alloc.c linux-2.5/mm/page_alloc.c
--- linux-2.5.73-mm2/mm/page_alloc.c 2003-07-01 19:59:57.000000000 +0100
+++ linux-2.5/mm/page_alloc.c 2003-07-02 01:12:09.000000000 +54,6 +154,7 @@
#define pfn_valid(pfn) ((pfn) < max_mapnr)
#endif /* !CONFIG_DISCONTIGMEM */
#define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
+#define phys_to_page(x) (mem_map + ((unsigned long)(x) >> PAGE_SHIFT))
#define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
diff -urN linux-2.5.73-mm2/mm/bootmem.c linux-2.5/mm/bootmem.c
--- linux-2.5.73-mm2/mm/bootmem.c 2003-06-17 05:19:47.000000000 +0100
+++ linux-2.5/mm/bootmem.c 2003-07-01 20:42:25.000000000 +0100
@@ -274,8 +274,17 @@
if (v & m) {
count++;
ClearPageReserved(page);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+
set_page_count(page, 1);
__free_page(page);
+#endif
}
}
} else {
@@ -294,8 +303,16 @@
for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) {
count++;
ClearPageReserved(page);
- set_page_count(page, 1);
+
+#ifdef CONFIG_BADRAM
+ if (!PageBad(page)) {
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+#else
+ set_page_count(page, 1);
__free_page(page);
+#endif
}
total += count;
bdata->node_bootmem_map = NULL;
diff -urN linux-2.5.73-mm2/mm/page_alloc.c linux-2.5/mm/page_alloc.c
--- linux-2.5.73-mm2/mm/page_alloc.c 2003-07-01 19:59:57.000000000 +0100
+++ linux-2.5/mm/page_alloc.c 2003-07-02 01:12:09.000000000 +0100
@@ -12,6 +12,7 @@
* Zone balancing, Kanoj Sarcar, SGI, Jan 2000
* Per cpu hot/cold page lists, bulk allocation, Martin J. Bligh, Sept 2002
* (lots of bits borrowed from Ingo Molnar & Andrew Morton)
+ * BadRAM handling, Rick van Rein, Feb 2001
*/
#include <linux/config.h>
@@ -1615,3 +1616,96 @@
setup_per_zone_pages_min();
return 0;
}
+
+
+#ifdef CONFIG_BADRAM
+
+/* Given a pointed-at address and a mask, increment the page so that the
+ * mask hides the increment. Return 0 if no increment is possible.
+ */
+static int __init next_masked_address (unsigned long *addrp, unsigned long mask)
+{
+ unsigned long inc=1;
+ unsigned long newval = *addrp;
+ while (inc & mask)
+ inc += inc;
+ while (inc != 0) {
+ newval += inc;
+ newval &= ~mask;
+ newval |= ((*addrp) & mask);
+ if (newval > *addrp) {
+ *addrp = newval;
+ return 1;
+ }
+ do {
+ inc += inc;
+ } while (inc & ~mask);
+ while (inc & mask)
+ inc += inc;
+ }
+ return 0;
+}
+
+
+void __init badram_markpages (int argc, unsigned long *argv) {
+ unsigned long addr, mask;
+ while (argc-- > 0) {
+ addr = *argv++;
+ mask = (argc-- > 0) ? *argv++ : ~0L;
+ mask |= ~PAGE_MASK; // Optimalisation
+ addr &= mask; // Normalisation
+ do {
+ struct page *pg = phys_to_page(addr);
+printk ("%05lx ", __pa(__va(addr)) >> PAGE_SHIFT);
+printk ("=%05lx/%05lx ", pg-mem_map, max_mapnr);
+ // if (VALID_PAGE(pg)) {
+ if (PageTestandSetBad (pg)) {
+ reserve_bootmem (addr, PAGE_SIZE);
+printk ("BAD ");
+ }
+else printk ("BFR ");
+ // }
+// else printk ("INV ");
+ } while (next_masked_address (&addr,mask));
+ }
+}
+
+
+
+/*********** CONFIG_BADRAM: CUSTOMISABLE SECTION STARTS HERE ******************/
+
+
+// Enter your custom BadRAM patterns here as pairs of unsigned long integers.
+// For more information on these F/M pairs, refer to Documentation/badram.txt
+
+
+static unsigned long __devinitdata badram_custom[] = {
+ 0, // Number of longwords that follow, as F/M pairs
+};
+
+
+/*********** CONFIG_BADRAM: CUSTOMISABLE SECTION ENDS HERE ********************/
+
+
+
+static int __init badram_setup (char *str)
+{
+ unsigned long opts[3];
+ if (!mem_map) BUG();
+printk ("PAGE_OFFSET=0x%08lx\n", PAGE_OFFSET);
+printk ("BadRAM option is %s\n", str);
+ if (*str++ == '=')
+ while (str=get_options (str, 3, (int *) opts), *opts) {
+printk (" --> marking 0x%08lx, 0x%08lx [%ld]\n", opts[1], opts[2], opts[0]);
+ badram_markpages (*opts, opts+1);
+ if (*opts==1)
+ break;
+ };
+ badram_markpages (*badram_custom, badram_custom+1);
+ return 0;
+}
+
+__setup("badram", badram_setup);
+
+#endif /* CONFIG_BADRAM */
+
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2003-07-02 12:58 Re: [PATCH] BadRAM for 2.5.73-mm2 steven.newbury1
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