Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932610Ab3CGOGc (ORCPT ); Thu, 7 Mar 2013 09:06:32 -0500 Received: from g6t0187.atlanta.hp.com ([15.193.32.64]:22272 "EHLO g6t0187.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755955Ab3CGOG3 (ORCPT ); Thu, 7 Mar 2013 09:06:29 -0500 Subject: [RFC PATCH 3/5] crash dump bitmap: scan memory pages in kernel crash process To: linux-kernel@vger.kernel.org From: Jingbai Ma Date: Thu, 07 Mar 2013 22:06:23 +0800 Message-ID: <20130307140622.28557.34463.stgit@k.asiapacific.hpqcorp.net> In-Reply-To: <20130307140546.28557.92853.stgit@k.asiapacific.hpqcorp.net> References: <20130307140546.28557.92853.stgit@k.asiapacific.hpqcorp.net> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6823 Lines: 225 In the kernel crash process, call generate_crash_dump_bitmap() to scans all memory pages, clear the bit for all excluded memory pages in the reserved memory. Signed-off-by: Jingbai Ma --- kernel/crash_dump_bitmap.c | 156 ++++++++++++++++++++++++++++++++++++++++++++ kernel/kexec.c | 5 + 2 files changed, 161 insertions(+), 0 deletions(-) diff --git a/kernel/crash_dump_bitmap.c b/kernel/crash_dump_bitmap.c index e743cdd..eed13ca 100644 --- a/kernel/crash_dump_bitmap.c +++ b/kernel/crash_dump_bitmap.c @@ -23,6 +23,8 @@ #ifdef CONFIG_CRASH_DUMP_BITMAP +#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) + phys_addr_t crash_dump_bitmap_mem; EXPORT_SYMBOL(crash_dump_bitmap_mem); @@ -35,6 +37,7 @@ EXPORT_SYMBOL(crash_dump_bitmap_ctrl); struct crash_dump_bitmap_info crash_dump_bitmap_info; EXPORT_SYMBOL(crash_dump_bitmap_info); + /* Location of the reserved area for the crash_dump_bitmap */ struct resource crash_dump_bitmap_res = { .name = "Crash dump bitmap", @@ -42,4 +45,157 @@ struct resource crash_dump_bitmap_res = { .end = 0, .flags = IORESOURCE_BUSY | IORESOURCE_MEM }; + +inline void set_crash_dump_bitmap(unsigned long pfn, int val) +{ + phys_addr_t paddr = crash_dump_bitmap_info.bitmap + (pfn >> 3); + unsigned char *vaddr; + unsigned char bit = (pfn & 7); + + if (unlikely(paddr > (crash_dump_bitmap_mem + + crash_dump_bitmap_mem_size))) { + pr_err( + "crash_dump_bitmap: pfn exceed limit. pfn=%ld, addr=0x%llX\n", + pfn, paddr); + return; + } + + vaddr = (unsigned char *)__va(paddr); + + if (val) + *vaddr |= (1U << bit); + else + *vaddr &= (~(1U << bit)); +} + +void generate_crash_dump_bitmap(void) +{ + pg_data_t *pgdat; + struct zone *zone; + unsigned long flags; + int order, t; + struct list_head *curr; + unsigned long zone_free_pages; + phys_addr_t addr; + + if (!crash_dump_bitmap_mem) { + pr_info("crash_dump_bitmap: no crash_dump_bitmap memory.\n"); + return; + } + + pr_info( + "Excluding pages: bitmap=%d, cache=%d, private=%d, user=%d, free=%d\n", + crash_dump_bitmap_ctrl.exclude_crash_dump_bitmap_pages, + crash_dump_bitmap_ctrl.exclude_cache_pages, + crash_dump_bitmap_ctrl.exclude_cache_private_pages, + crash_dump_bitmap_ctrl.exclude_user_pages, + crash_dump_bitmap_ctrl.exclude_free_pages); + + crash_dump_bitmap_info.free_pages = 0; + crash_dump_bitmap_info.cache_pages = 0; + crash_dump_bitmap_info.cache_private_pages = 0; + crash_dump_bitmap_info.user_pages = 0; + crash_dump_bitmap_info.hwpoison_pages = 0; + + /* Set all bits on bitmap */ + memset(__va(crash_dump_bitmap_info.bitmap), 0xff, + crash_dump_bitmap_info.bitmap_size); + + /* Exclude all crash_dump_bitmap pages */ + if (crash_dump_bitmap_ctrl.exclude_crash_dump_bitmap_pages) { + for (addr = crash_dump_bitmap_mem; addr < + crash_dump_bitmap_mem + crash_dump_bitmap_mem_size; + addr += PAGE_SIZE) + set_crash_dump_bitmap( + virt_to_pfn(__va(addr)), 0); + } + + /* Exclude unnecessary pages */ + for_each_online_pgdat(pgdat) { + unsigned long i; + unsigned long flags; + + pgdat_resize_lock(pgdat, &flags); + for (i = 0; i < pgdat->node_spanned_pages; i++) { + struct page *page; + unsigned long pfn = pgdat->node_start_pfn + i; + + if (!pfn_valid(pfn)) + continue; + + page = pfn_to_page(pfn); + + /* Exclude the cache pages without the private page */ + if (crash_dump_bitmap_ctrl.exclude_cache_pages + && (PageLRU(page) || PageSwapCache(page)) + && !page_has_private(page) && !PageAnon(page)) { + set_crash_dump_bitmap(pfn, 0); + crash_dump_bitmap_info.cache_pages++; + } + /* Exclude the cache pages with private page */ + else if ( + crash_dump_bitmap_ctrl.exclude_cache_private_pages + && (PageLRU(page) || PageSwapCache(page)) + && !PageAnon(page)) { + set_crash_dump_bitmap(pfn, 0); + crash_dump_bitmap_info.cache_private_pages++; + } + /* Exclude the pages used by user process */ + else if (crash_dump_bitmap_ctrl.exclude_user_pages + && PageAnon(page)) { + set_crash_dump_bitmap(pfn, 0); + crash_dump_bitmap_info.user_pages++; + } +#ifdef CONFIG_MEMORY_FAILURE + /* Exclude the hwpoison pages */ + else if (PageHWPoison(page)) { + set_crash_dump_bitmap(pfn, 0); + crash_dump_bitmap_info.hwpoison_pages++; + } +#endif + } + pgdat_resize_unlock(pgdat, &flags); + } + + /* Exclude the free pages managed by a buddy system */ + if (crash_dump_bitmap_ctrl.exclude_free_pages) { + for_each_populated_zone(zone) { + if (!zone->spanned_pages) + continue; + + spin_lock_irqsave(&zone->lock, flags); + + zone_free_pages = 0; + for_each_migratetype_order(order, t) { + list_for_each( + curr, &zone->free_area[order].free_list[t]) { + unsigned long i; + struct page *page = list_entry(curr, + struct page, lru); + for (i = 0; i < (1 << order); i++) { + set_crash_dump_bitmap( + page_to_pfn(page + i), 0); + zone_free_pages++; + crash_dump_bitmap_info.free_pages++; + } + } + } + spin_unlock_irqrestore(&zone->lock, flags); + } + } + + pr_info("crash_dump_bitmap: excluded pages: cache=%ld, private=%ld\n", + crash_dump_bitmap_info.cache_pages, + crash_dump_bitmap_info.cache_private_pages); + pr_info("crash_dump_bitmap: excluded pages: user=%ld, free=%ld\n", + crash_dump_bitmap_info.user_pages, + crash_dump_bitmap_info.free_pages); + pr_info("crash_dump_bitmap: excluded pages: hwpoison=%ld\n", + crash_dump_bitmap_info.hwpoison_pages); +} +EXPORT_SYMBOL(generate_crash_dump_bitmap); +#else +void generate_crash_dump_bitmap(void) +{ +} #endif /* CONFIG_CRASH_DUMP_BITMAP */ diff --git a/kernel/kexec.c b/kernel/kexec.c index bddd3d7..ce00f0f 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -1097,6 +1098,7 @@ void crash_kexec(struct pt_regs *regs) crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); + generate_crash_dump_bitmap(); machine_kexec(kexec_crash_image); } mutex_unlock(&kexec_mutex); @@ -1495,6 +1497,9 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_SYMBOL(mem_map); VMCOREINFO_SYMBOL(contig_page_data); #endif +#ifdef CONFIG_CRASH_DUMP_BITMAP + VMCOREINFO_SYMBOL(crash_dump_bitmap_info); +#endif #ifdef CONFIG_SPARSEMEM VMCOREINFO_SYMBOL(mem_section); VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/