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On Wed, 19 Oct 2005, Takao Indoh wrote: > > > > Could you briefly explain the implementation of partial dump in > > diskdump for those who are not familiar with it?> > > > - Levels of partial dump (supported page categories) > > - How to indentify the category (kernel data structure used)> > Ok.> Partial dump of diskdump defines 5 filters.> > #define DUMP_EXCLUDE_CACHE 0x00000001 /* Exclude LRU & SwapCache pages*/ > #define DUMP_EXCLUDE_CLEAN 0x00000002 /* Exclude all-zero pages */ > #define DUMP_EXCLUDE_FREE 0x00000004 /* Exclude free pages */ > #define DUMP_EXCLUDE_ANON 0x00000008 /* Exclude Anon pages */ > #define DUMP_SAVE_PRIVATE 0x00000010 /* Save private pages */ > DUMP_EXCLUDE_FREE has some risks. If this filter is enable, diskdump > scans free page linked lists. If the list is corrupt, diskdump may hang. > Therefore, I always use level-19 (EXCLUDE_CACHE & EXCLUDE_CLEAN & > SAVE_PRIVATE). > > DUMP_EXCLUDE_CACHE reduces dump size effectively when file caches on > memory are big. I don't use DUMP_EXCLUDE_ANON because user data(user > stack, thread stack, mutex, etc.) is sometimes needed to investigate > dump. > DUMP_SAVE_PRIVATE is needed for filesystem. Filesystem (journal) uses > PG_private pages, so these pages is necessary to investigate > trouble of filesystem. Thank you for filters' description as well as the recommended filter combination. I'm just wondering the use of DUMP_EXCLUDE_CLEAN. When a zero page is excluded from a dump, how people know? What I'm afraid is that people would see an error (e.g., no such page in a dump) in analyzing such a dump and be confused why. Because it is a cache, or zero-cleared, or, ...? Any ideas? Regards, -- OBATA Noboru (noboru.obata.ar@hitachi.com) - 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/ | |||||||||
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