Atsushi, do you have speed measurements for saving vmcore with this patches and without them? How much is speed up? Thanks, Maxim. 2012/5/31 Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp> > Hello, > > I made the prototype of cyclic processing to keep memory consumption. > I attache the patch set based on v1.4.4, I would like to get your advice. > > Introduction: > > - The basic idea of cyclic processing is represented as below. > - cyclic processing doesn't use temporary bitmap file, store partial > bitmap data > in memory only for each cycle instead. > - The prototype only support compressed kdump format. > - The prototype worked for almost kernel version except some kernel > disabled PAE > in my environment. > > Basic idea (HATAYAMA-san wrote): > > +------------------------------------------+ > | main header (struct disk_dump_header) | > |------------------------------------------+ > | sub header (struct kdump_sub_header) | > |------------------------------------------+ > | | <-- 1st cycle > | - - - - - - - - - - - - - - | > | 1st-bitmap | <-- 2nd cycle > | - - - - - - - - - - - - - - | > | | <-- 3rd cycle > |------------------------------------------+ > | | <-- 1st cycle > | - - - - - - - - - - - - - - | > | 2nd-bitmap | <-- 2nd cycle > | - - - - - - - - - - - - - - | > | | <-- 3rd cycle > |------------------------------------------+ > | | <-- 1st cycle > | - - - - - - - - - - - - - - | > | page header | <-- 2nd cycle > | - - - - - - - - - - - - - - | > | | <-- 3rd cycle > |------------------------------------------| > | | > | page data | <-- 1st cycle > | | > | - - - - - - - - - - - - - - | > | page data | <-- 2nd cycle > | - - - - - - - - - - - - - - | > | | > | | > | page data | <-- 3rd cycle > | | > | | > +------------------------------------------+ > > > How to use: > > Specify 'K' option, then makedumpfile works cyclically. > > Example: > > a. normal processing: > > $ makedumpfile -cd31 vmcore testdump.cd31 > Copying data : [100 %] > > The dumpfile is saved to testdump.cd31. > > makedumpfile Completed. > > b. cyclic processing (too many messages will be displayed): > > $ makedumpfile -Kcd31 vmcore testdump.Kcd31 > Copying data : [ 5 %] > Excluding free pages : [100 %] > ... > Excluding free pages : [100 %] > Copying data : [100 %] > > The dumpfile is saved to testdump.Kcd31. > > makedumpfile Completed. > > c. compare each dumpfiles: > > $ cmp testdump.cd31 testdump.Kcd31 > $ > > TODO: > > - Optimize code for performance. > (e.g. initialize for compression is done every cycle, it's a waste.) > - Support ELF format. > - Consider suitable size of target region. > - Fix some messages. > - And something noticed by you. > > > Thanks > Atsushi Kumagai > > _______________________________________________ > kexec mailing list > kexec at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > -- Best regards, Maxim Uvarov -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.infradead.org/pipermail/kexec/attachments/20120626/6c310d47/attachment.html>
