* RE: My own 3.5G patch - there was a bug in the patch I started with
2003-07-10 23:02 ` Dave Hansen
@ 2003-07-10 23:24 ` Chuck Luciano
0 siblings, 0 replies; 5+ messages in thread
From: Chuck Luciano @ 2003-07-10 23:24 UTC (permalink / raw)
To: Linux-Kernel
[-- Attachment #1: Type: text/plain, Size: 2478 bytes --]
I almost forgot. The patch I started with had a bug in it. (This is in case
anybody is using that patch)
+#define USER_PTRS_PER_PMD(x) ((PARTIAL_PGD && ((x)==USER_PTRS_PER_PGD-1)) ? \
+ (PTRS_PER_PMD-PARTIAL_PMD) : \
+ PTRS_PER_PMD)
I had to change this to:
#define USER_PTRS_PER_PMD(x) ((PARTIAL_PGD && ((x)==USER_PTRS_PER_PGD-1)) ? \
PARTIAL_PMD : \
PTRS_PER_PMD)
before my change, it worked at 1Gig boundarys (ok, i really only tested at 0xc0000000) and
at 1gig + .5Gig boundarys (e.g. 0xe0000000), 0xd0000000 would blow up, and I think 0xe8000000
was leaking some memory somewhere.
Anyway, the math was backwards.
> -----Original Message-----
> From: Dave Hansen [mailto:haveblue@us.ibm.com]
> Sent: Thursday, July 10, 2003 5:02 PM
> To: Chuck Luciano
> Cc: Linux-Kernel
> Subject: Re: My own 3.5G patch plus question on Ingo's 4G/$G patch
>
>
> On Thu, 2003-07-10 at 12:09, Chuck Luciano wrote:
> > I've been working on a patch for 2.4.18 that allows PAGE_OFFSET
> > to be set on boundarys other then 1GB multiples. I started with
> > a patch that I got from Martin Bligh and back ported it to 2.4.18.
>
> I stole the configurable PAGE_OFFSET code from Andrea, made it work with
> partial kernel pmds, and stuck it in Martin's tree. There are several
> parts to it, and I'm not sure which ones you got.
>
> > http://www.mrluciano.com/chuck/linux-2.4.18-unaligned.patch
> >
> > I'll apologize in advance for not having figured out how the configure
> > system works, so, when you apply this patch it's on. Also, you have to
> > edit vmlinux.lds AND page.h to move the boundary.
>
> Here's the 2.5 patch to do the configuration:
> http://ftp.kernel.org/pub/linux/kernel/people/mbligh/patches/2.5.73/2.5.73-mjb1/102-config_page_offset
> You'll have to adapt the arch/i386/Kconfig stuff to 2.4, but there's a
> good example of it here:
> http://ftp.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.21rc8aa1/00_3.5G-address-space-5
> (which is where I stole the code from to begin with)
Thank you. The first time through, I was mainly concerned with getting it all to work. This time I'll
make it configurable.
>
> Instead of changing _all_ of the loops which touch PMDs, I suggest you
> clean it up inside of the pmd function themselves. All of these are
> confusing:
> + if (start + PGDIR_SIZE < start)
> + break;
>
Duely noted.
>
> --
> Dave Hansen
> haveblue@us.ibm.com
>
Thank you,
Chuck L.
[-- Attachment #2: unaligned-page_offset-pae-2.4.19-UL-0.patch --]
[-- Type: application/octet-stream, Size: 8747 bytes --]
Binary files linux-2.4.19-suse/Kerntypes and linux-2.4.19-suse-weirdoffset/Kerntypes differ
diff -ur linux-2.4.19-suse/arch/i386/config.in linux-2.4.19-suse-weirdoffset/arch/i386/config.in
--- linux-2.4.19-suse/arch/i386/config.in Tue Jan 14 14:44:06 2003
+++ linux-2.4.19-suse-weirdoffset/arch/i386/config.in Mon Jan 20 08:59:28 2003
@@ -193,7 +193,9 @@
define_bool CONFIG_X86_PAE y
define_int CONFIG_FORCE_MAX_ZONEORDER 10
choice 'User address space size' \
- "3GB CONFIG_1GB \
+ "3.75GB CONFIG_025GB \
+ 3.5GB CONFIG_05GB \
+ 3GB CONFIG_1GB \
2GB CONFIG_2GB \
1GB CONFIG_3GB" 3GB
else
diff -ur linux-2.4.19-suse/arch/i386/mm/init.c linux-2.4.19-suse-weirdoffset/arch/i386/mm/init.c
--- linux-2.4.19-suse/arch/i386/mm/init.c Tue Jan 14 14:43:57 2003
+++ linux-2.4.19-suse-weirdoffset/arch/i386/mm/init.c Mon Jan 20 09:09:24 2003
@@ -214,6 +214,107 @@
}
}
+#define pte_offset_kernel(dir, address) \
+ ((pte_t *) pmd_page_kernel(*(dir)) + __pte_offset(address))
+#define pmd_page_kernel(pmd) \
+ ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+/*
+ * Create a page table and place a pointer to it in a middle page
+ * directory entry.
+ */
+static pte_t * __init one_page_table_init(pmd_t *pmd)
+{
+ pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+ set_pmd(pmd, __pmd(__pa(page_table) | _KERNPG_TABLE));
+ if (page_table != pte_offset_kernel(pmd, 0))
+ BUG();
+
+ return page_table;
+}
+
+
+/*
+ * Abstract out using large pages when mapping KVA, or the SMP identity
+ * mapping
+ */
+static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
+{
+ return __pmd(((unsigned long long)page_nr << PAGE_SHIFT) | pgprot_val(pgprot));
+}
+static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
+{
+ pte_t pte;
+
+ pte.pte_high = page_nr >> (32 - PAGE_SHIFT);
+ pte.pte_low = (page_nr << PAGE_SHIFT) | pgprot_val(pgprot);
+ return pte;
+}
+
+#define __PAGE_KERNEL_LARGE (__PAGE_KERNEL | _PAGE_PSE)
+#define PAGE_KERNEL_LARGE __pgprot(__PAGE_KERNEL_LARGE)
+/*
+ * Creates a middle page table and puts a pointer to it in the
+ * given global directory entry. This only returns the gd entry
+ * in non-PAE compilation mode, since the middle layer is folded.
+ */
+static pmd_t * __init one_md_table_init(pgd_t *pgd)
+{
+ pmd_t *pmd_table;
+
+#if CONFIG_X86_PAE
+ pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+ set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
+ if (pmd_table != pmd_offset(pgd, 0))
+ BUG();
+#else
+ pmd_table = pmd_offset(pgd, 0);
+#endif
+ return pmd_table;
+}
+
+void pmd_map_pfn_range(pmd_t* pmd_entry, unsigned long pfn, unsigned long max_pfn)
+{
+ int pte_ofs;
+ /* Map with big pages if possible, otherwise create normal page tables. */
+ if (cpu_has_pse) {
+ set_pmd(pmd_entry, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+ pfn += PTRS_PER_PTE;
+ } else {
+ pte_t* pte = one_page_table_init(pmd_entry);
+ for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE && pfn < max_pfn; pte++, pfn++, pte_ofs++)
+ set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
+ }
+}
+
+
+/*
+ * Add low memory identity-mappings - SMP needs it when
+ * starting up on an AP from real-mode. In the non-PAE
+ * case we already have these mappings through head.S.
+ * All user-space mappings are explicitly cleared after
+ * SMP startup in zap_low_mappings().
+ */
+static void __init low_physical_mapping_init(pgd_t *pgd_base)
+{
+#if CONFIG_X86_PAE
+ unsigned long pfn = 0;
+ int pmd_ofs = 0;
+ pmd_t *pmd = one_md_table_init(pgd_base);
+
+ if(!cpu_has_pse) {
+ printk("PAE enabled, but no support for PSE (large pages)!");
+ printk("this is likely to waste some RAM.");
+ }
+
+ for (; pmd_ofs < PTRS_PER_PMD && pfn <= max_low_pfn; pmd++, pmd_ofs++) {
+ pmd_map_pfn_range(pmd, pfn, max_low_pfn);
+ pfn += PTRS_PER_PTE;
+ }
+#endif
+
+}
+
+
void __init pagetable_init (void)
{
unsigned long vaddr, end;
@@ -240,14 +341,7 @@
set_pgd(pgd_base + i, __pgd(1 + __pa(empty_zero_page)));
for (; i < PTRS_PER_PGD; i++, pmd += PTRS_PER_PMD)
set_pgd(pgd_base + i, __pgd(1 + __pa(pmd)));
- /*
- * Add low memory identity-mappings - SMP needs it when
- * starting up on an AP from real-mode. In the non-PAE
- * case we already have these mappings through head.S.
- * All user-space mappings are explicitly cleared after
- * SMP startup.
- */
- pgd_base[0] = pgd_base[USER_PGD_PTRS];
+ low_physical_mapping_init(pgd_base);
#endif
i = __pgd_offset(PAGE_OFFSET);
pgd = pgd_base + i;
@@ -318,13 +412,14 @@
void __init zap_low_mappings (void)
{
int i;
+ printk("zap_low_mappings()\n");
/*
* Zap initial low-memory mappings.
*
* Note that "pgd_clear()" doesn't do it for
* us, because pgd_clear() is a no-op on i386.
*/
- for (i = 0; i < USER_PTRS_PER_PGD; i++)
+ for (i = 0; i < __USER_PTRS_PER_PGD; i++)
#if CONFIG_X86_PAE
set_pgd(swapper_pg_dir+i, __pgd(1 + __pa(empty_zero_page)));
#else
diff -ur linux-2.4.19-suse/include/asm-i386/page_offset.h linux-2.4.19-suse-weirdoffset/include/asm-i386/page_offset.h
--- linux-2.4.19-suse/include/asm-i386/page_offset.h Tue Jan 14 14:46:33 2003
+++ linux-2.4.19-suse-weirdoffset/include/asm-i386/page_offset.h Mon Jan 20 09:00:23 2003
@@ -1,5 +1,7 @@
#include <linux/config.h>
-#ifdef CONFIG_05GB
+#ifdef CONFIG_025GB
+#define PAGE_OFFSET_RAW 0xF0000000
+#elif defined(CONFIG_05GB)
#define PAGE_OFFSET_RAW 0xE0000000
#elif defined(CONFIG_1GB)
#define PAGE_OFFSET_RAW 0xC0000000
diff -ur linux-2.4.19-suse/include/asm-i386/pgalloc.h linux-2.4.19-suse-weirdoffset/include/asm-i386/pgalloc.h
--- linux-2.4.19-suse/include/asm-i386/pgalloc.h Tue Jan 14 14:46:34 2003
+++ linux-2.4.19-suse-weirdoffset/include/asm-i386/pgalloc.h Mon Jan 20 09:00:23 2003
@@ -44,7 +44,6 @@
{
int i;
pgd_t *pgd = kmem_cache_alloc(pae_pgd_cachep, GFP_KERNEL);
-
if (pgd) {
for (i = 0; i < USER_PTRS_PER_PGD; i++) {
unsigned long pmd = __get_free_page(GFP_KERNEL);
@@ -53,9 +52,21 @@
clear_page(pmd);
set_pgd(pgd + i, __pgd(1 + __pa(pmd)));
}
- memcpy(pgd + USER_PTRS_PER_PGD,
- swapper_pg_dir + USER_PTRS_PER_PGD,
- (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+ if (USER_PTRS_PER_PGD < PTRS_PER_PGD)
+ memcpy(pgd + USER_PTRS_PER_PGD,
+ swapper_pg_dir + USER_PTRS_PER_PGD,
+ (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+ if (PARTIAL_PGD) {
+ pgd_t *kpgd, *upgd;
+ pmd_t *kpmd, *upmd;
+
+ kpgd = pgd_offset_k(TASK_SIZE);
+ upgd = pgd + __pgd_offset(TASK_SIZE);
+ kpmd = pmd_offset(kpgd, TASK_SIZE);
+ upmd = pmd_offset(upgd, TASK_SIZE);
+ memcpy(upmd, kpmd, (PTRS_PER_PMD-PARTIAL_PMD)*sizeof(pmd_t));
+ }
+
}
return pgd;
out_oom:
diff -ur linux-2.4.19-suse/include/asm-i386/pgtable.h linux-2.4.19-suse-weirdoffset/include/asm-i386/pgtable.h
--- linux-2.4.19-suse/include/asm-i386/pgtable.h Tue Jan 14 14:46:34 2003
+++ linux-2.4.19-suse-weirdoffset/include/asm-i386/pgtable.h Mon Jan 20 09:00:23 2003
@@ -138,7 +138,14 @@
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
-#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
+#define __USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
+#define PARTIAL_PGD (TASK_SIZE > __USER_PTRS_PER_PGD*PGDIR_SIZE ? 1 : 0)
+#define PARTIAL_PMD ((TASK_SIZE % PGDIR_SIZE)/PMD_SIZE)
+#define USER_PTRS_PER_PGD (PARTIAL_PGD + __USER_PTRS_PER_PGD)
+#define USER_PTRS_PER_PMD(x) ((PARTIAL_PGD && ((x)==USER_PTRS_PER_PGD-1)) ? \
+ (PTRS_PER_PMD-PARTIAL_PMD) : \
+ PTRS_PER_PMD)
+
#define FIRST_USER_PGD_NR 0
#define USER_PGD_PTRS (PAGE_OFFSET >> PGDIR_SHIFT)
diff -ur linux-2.4.19-suse/mm/memory.c linux-2.4.19-suse-weirdoffset/mm/memory.c
--- linux-2.4.19-suse/mm/memory.c Tue Jan 14 14:44:06 2003
+++ linux-2.4.19-suse-weirdoffset/mm/memory.c Mon Jan 20 08:12:41 2003
@@ -111,10 +111,11 @@
pte_free_via_pmd(pmd);
}
-static inline void free_one_pgd(pgd_t * dir)
+static inline void free_one_pgd(pgd_t * pgd, unsigned long pgdi)
{
pmd_t * pmd, * md, * emd;
-
+ pgd_t *dir = pgd + pgdi;
+
if (pgd_none(*dir))
return;
if (pgd_bad(*dir)) {
@@ -138,7 +139,7 @@
* found at 0x80000000 onwards. The loop below compiles instead
* to be terminated by unsigned address comparison using "jb".
*/
- for (md = pmd, emd = pmd + PTRS_PER_PMD; md < emd; md++) {
+ for (md = pmd, emd = pmd + USER_PTRS_PER_PMD(pgdi); md < emd; md++) {
prefetchw(md+(PREFETCH_STRIDE/16));
free_one_pmd(md);
}
@@ -165,12 +166,12 @@
{
pgd_t * page_dir = mm->pgd;
unsigned long last = first + nr;
+ int index = first;
spin_lock(&mm->page_table_lock);
- page_dir += first;
do {
- free_one_pgd(page_dir);
- page_dir++;
+ free_one_pgd(page_dir, index);
+ index++;
} while (--nr);
spin_unlock(&mm->page_table_lock);
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