2011/12/29 Bojan Smojver <bojan@xxxxxxxxxxxxx>: > On Thu, 2011-12-29 at 11:20 +0800, Barry Song wrote: >> the platform is ARM cortex-a9 single-core 1Ghz SoC and we save image >> to a SD card or NAND. >> a phenomenon we saw is that multi-BIOs is not merged into a request by >> block level elevator. so the SD/NANDdisk driver handles many small >> request one page by one page. > > Interesting, thanks. we did see some visible IO performance improvement now. the main reason we didn't see that before is because we enable on-demand cpufreq in default status. while saving and resuming from snapshot, cpu frequence is switched frequently due to IO sleep and compression/uncompression CPU consume. then we enable Performance policy while booting, and move to on-demand after system boot, we did see a great performance improvement. for our inand card, the speed to read/uncompress snapshot is improved from 7.x MB to 11MB. > > -- > Bojan > -barry _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
