From: Ben Gras Date: Sun, 24 Feb 2013 21:00:52 +0000 (+0100) Subject: VM: pagetable.c: harmonize x86/ARM findhole() code X-Git-Tag: v3.3.0~1090 X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/openssl_button.gif?a=commitdiff_plain;h=refs%2Fchanges%2F84%2F384%2F3;p=minix.git VM: pagetable.c: harmonize x86/ARM findhole() code ARM needs to be able to find N consecutive free slots; use same code for x86. Change-Id: Ic79677961c8adfca2aeb5385962942ae0d76867c --- diff --git a/servers/vm/alloc.c b/servers/vm/alloc.c index 5489eff0b..23088ffee 100644 --- a/servers/vm/alloc.c +++ b/servers/vm/alloc.c @@ -54,7 +54,7 @@ struct { #define page_isfree(i) GET_BIT(free_pages_bitmap, i) #define RESERVEDMAGIC 0x6e4c74d5 -#define MAXRESERVEDPAGES 100 +#define MAXRESERVEDPAGES 300 #define MAXRESERVEDQUEUES 15 static struct reserved_pages { diff --git a/servers/vm/arch/i386/pagetable.c b/servers/vm/arch/i386/pagetable.c index 85ab481cc..0605ccbc6 100644 --- a/servers/vm/arch/i386/pagetable.c +++ b/servers/vm/arch/i386/pagetable.c @@ -44,8 +44,6 @@ static struct pdm { u32_t *page_directories; } pagedir_mappings[MAX_PAGEDIR_PDES]; -static u32_t global_bit = 0; - static multiboot_module_t *kern_mb_mod = NULL; static size_t kern_size = 0; static int kern_start_pde = -1; @@ -61,13 +59,14 @@ struct vmproc *vmprocess = &vmproc[VM_PROC_NR]; * page table. */ #if SANITYCHECKS -#define SPAREPAGES 100 -#define STATIC_SPAREPAGES 90 +#define SPAREPAGES 200 +#define STATIC_SPAREPAGES 190 #else #ifdef __arm__ # define SPAREPAGES 150 # define STATIC_SPAREPAGES 140 #else +static u32_t global_bit = 0; # define SPAREPAGES 20 # define STATIC_SPAREPAGES 15 #endif /* __arm__ */ @@ -150,23 +149,20 @@ static u32_t findhole(int pages) static u32_t lastv = 0; pt_t *pt = &vmprocess->vm_pt; vir_bytes vmin, vmax; -#if defined(__arm__) - u32_t holev; -#endif + u32_t holev = NO_MEM; + int holesize = -1; vmin = (vir_bytes) (&_end); /* marks end of VM BSS */ vmin += 1024*1024*1024; /* reserve 1GB virtual address space for VM heap */ vmin &= ARCH_VM_ADDR_MASK; - vmax = VM_STACKTOP; + vmax = vmin + 100 * 1024 * 1024; /* allow 100MB of address space for VM */ /* Input sanity check. */ assert(vmin + VM_PAGE_SIZE >= vmin); assert(vmax >= vmin + VM_PAGE_SIZE); assert((vmin % VM_PAGE_SIZE) == 0); assert((vmax % VM_PAGE_SIZE) == 0); -#if defined(__arm__) assert(pages > 0); -#endif curv = lastv; if(curv < vmin || curv >= vmax) @@ -177,9 +173,6 @@ static u32_t findhole(int pages) /* Start looking for a free page starting at vmin. */ while(curv < vmax) { int pte; -#if defined(__arm__) - int i, nohole; -#endif assert(curv >= vmin); assert(curv < vmax); @@ -188,53 +181,42 @@ static u32_t findhole(int pages) pde = I386_VM_PDE(curv); pte = I386_VM_PTE(curv); #elif defined(__arm__) - holev = curv; /* the candidate hole */ - nohole = 0; - for (i = 0; i < pages && !nohole; ++i) { - if(curv >= vmax) { - break; - } + pde = ARM_VM_PDE(curv); + pte = ARM_VM_PTE(curv); #endif -#if defined(__i386__) - if(!(pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) || - !(pt->pt_pt[pde][pte] & ARCH_VM_PAGE_PRESENT)) { -#elif defined(__arm__) - pde = ARM_VM_PDE(curv); - pte = ARM_VM_PTE(curv); - - /* if page present, no hole */ - if((pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) && - (pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT)) - nohole = 1; - - /* if not contiguous, no hole */ - if (curv != holev + i * VM_PAGE_SIZE) - nohole = 1; - - curv+=VM_PAGE_SIZE; - } - - /* there's a large enough hole */ - if (!nohole && i == pages) { -#endif - lastv = curv; -#if defined(__i386__) - return curv; -#elif defined(__arm__) - return holev; -#endif + if((pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) && + (pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT)) { + /* there is a page here - so keep looking for holes */ + holev = NO_MEM; + holesize = 0; + } else { + /* there is no page here - so we have a hole, a bigger + * one if we already had one + */ + if(holev == NO_MEM) { + holev = curv; + holesize = 1; + } else holesize++; + + assert(holesize > 0); + assert(holesize <= pages); + + /* if it's big enough, return it */ + if(holesize == pages) { + lastv = curv + VM_PAGE_SIZE; + return holev; + } } -#if defined(__i386__) curv+=VM_PAGE_SIZE; -#elif defined(__arm__) - /* Reset curv */ -#endif + /* if we reached the limit, start scanning from the beginning if + * we haven't looked there yet + */ if(curv >= vmax && try_restart) { - curv = vmin; try_restart = 0; + curv = vmin; } } @@ -785,6 +767,31 @@ void pt_clearmapcache(void) panic("VMCTL_CLEARMAPCACHE failed"); } +int pt_writable(struct vmproc *vmp, vir_bytes v) +{ + u32_t entry; + pt_t *pt = &vmp->vm_pt; + assert(!(v % VM_PAGE_SIZE)); +#if defined(__i386__) + int pde = I386_VM_PDE(v); + int pte = I386_VM_PTE(v); +#elif defined(__arm__) + int pde = ARM_VM_PDE(v); + int pte = ARM_VM_PTE(v); +#endif + + assert(pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT); + assert(pt->pt_pt[pde]); + + entry = pt->pt_pt[pde][pte]; + +#if defined(__i386__) + return((entry & PTF_WRITE) ? 1 : 0); +#elif defined(__arm__) + return((entry & ARCH_VM_PTE_RO) ? 0 : 1); +#endif +} + /*===========================================================================* * pt_writemap * *===========================================================================*/ @@ -1443,6 +1450,27 @@ int pt_mapkernel(pt_t *pt) /* Kernel also wants various mappings of its own. */ for(i = 0; i < kernmappings; i++) { int r; +#if defined(__arm__) + if(kern_mappings[i].phys_addr == 0x48000000) { + addr = kern_mappings[i].phys_addr; + assert(!(kern_mappings[i].len % ARCH_BIG_PAGE_SIZE)); + for(mapped = 0; mapped < kern_mappings[i].len; + mapped += ARCH_BIG_PAGE_SIZE) { + int map_pde = addr / ARCH_BIG_PAGE_SIZE; + assert(!(addr % ARCH_BIG_PAGE_SIZE)); + assert(addr == (addr & ARCH_VM_PDE_MASK)); + assert(!pt->pt_dir[map_pde]); + pt->pt_dir[map_pde] = addr | + ARM_VM_SECTION | ARM_VM_SECTION_DOMAIN | + ARM_VM_SECTION_WB | + ARM_VM_SECTION_SHAREABLE | + ARM_VM_SECTION_SUPER; + addr += ARCH_BIG_PAGE_SIZE; + } + continue; + } +#endif + if((r=pt_writemap(NULL, pt, kern_mappings[i].vir_addr, kern_mappings[i].phys_addr, @@ -1451,17 +1479,6 @@ int pt_mapkernel(pt_t *pt) return r; } -#if defined(__arm__) - if(kern_mappings[i].phys_addr == 0x48000000) { - if((r=pt_writemap(NULL, pt, - kern_mappings[i].phys_addr, - kern_mappings[i].phys_addr, - kern_mappings[i].len, - kern_mappings[i].flags, 0)) != OK) { - return r; - } - } -#endif } return OK;