Hi Namjae, > -----Original Message----- > From: Namjae Jeon [mailto:linkinjeon@xxxxxxxxx] > Sent: Wednesday, April 18, 2012 11:12 AM > To: Subhash Jadavani > Cc: Chris Ball; linux-mmc@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v1 1/1] mmc: block: replace __blk_end_request() with > blk_end_request() > > Hi. Subhash. > > Would you share which option you used in LMDD, iozone test ? Following are the commands. Page cache is flushed before next iteration. Original numbers shared were average of almost 10 iterations. LMDD: 100MB file read/write: write: lmdd if=internal of=/data/datafile bs=128k count=800 flush=1 sync=1 read: lmdd if=/data/datafile of=internal bs=128k flush=1 sync=1 IOZONE: 100MB file read/write: Write: iozone -i0 -s100m -r128k -e -w -f /data/datafile -U /data/ Read: iozone -i1 -s100m -r128k -e -f /data/datafile -U /data/ Regards, Subhash > > Thanks. > > 2012/4/18 Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>: > > Hi Chris, > > > >> -----Original Message----- > >> From: linux-arm-msm-owner@xxxxxxxxxxxxxxx [mailto:linux-arm-msm- > >> owner@xxxxxxxxxxxxxxx] On Behalf Of Subhash Jadavani > >> Sent: Wednesday, April 11, 2012 12:22 AM > >> To: 'Chris Ball' > >> Cc: linux-mmc@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx > >> Subject: RE: [PATCH v1 1/1] mmc: block: replace __blk_end_request() > >> with > >> blk_end_request() > >> > >> > >> > >> > -----Original Message----- > >> > From: Chris Ball [mailto:cjb@xxxxxxxxxx] > >> > Sent: Wednesday, April 11, 2012 12:08 AM > >> > To: Subhash Jadavani > >> > Cc: linux-mmc@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx > >> > Subject: Re: [PATCH v1 1/1] mmc: block: replace __blk_end_request() > >> > with > >> > blk_end_request() > >> > > >> > Hi, > >> > > >> > On Tue, Apr 10 2012, Subhash Jadavani wrote: > >> > > This patch replaces all __blk_end_request() calls with > >> > > blk_end_request() and __blk_end_request_all() calls with > >> > > blk_end_request_all(). > >> > > > >> > > Testing done: 20 process concurrent read/write on sd card and eMMC. > >> > > Ran this test for almost a day on multicore system and no errors > >> > > observed. > >> > > >> > Is there a measurable improvement in throughput or latency that you > >> > can > >> show > >> > data for? > >> > >> This change was not meant for improving MMC throughput; it's > >> basically > > about > >> becoming fair to other threads/interrupts in the system. By holding > >> spin > > lock > >> and interrupts disabled for longer duration, we won't allow other > >> threads/interrupts to run at all. > >> Actually slight performance degradation at file system level can be > > expected as > >> we are not holding the spin lock during blk_update_bidi_request() > >> which > > means > >> our mmcqd thread may get preempted for other high priority thread or > >> any interrupt in the system. > >> > >> > >> These are performance numbers (100MB file write) with eMMC running in > >> DDR > >> mode: > >> > >> Without this patch: > >> Name of the Test Value Unit > >> LMDD Read Test 53.79 MBPS > >> LMDD Write Test 18.86 MBPS > >> IOZONE Read Test 51.65 MBPS > >> IOZONE Write Test 24.36 MBPS > >> > >> With this patch: > >> > >> Name of the Test Value Unit > >> LMDD Read Test 52.94 MBPS > >> LMDD Write Test 16.70 MBPS > >> IOZONE Read Test 52.08 MBPS > >> IOZONE Write Test 23.29 MBPS > >> > >> Read numbers are fine. Write numbers are bit down (especially LMDD > >> write), may be because write requests normally have large transfer > >> size and which means there are chances that while mmcq is executing > >> blk_update_bidi_request(), it may get interrupted by interrupts or > >> other > > high > >> priority thread. > > > > Any thoughts/suggestions on this patch and numbers? > > > > Regards, > > Subhash > >> > >> Regards, > >> Subhash > >> > >> > > >> > Thanks, > >> > > >> > - Chris. > >> > -- > >> > Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> One Laptop Per > >> > Child > >> > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" > > in the > >> body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at > >> http://vger.kernel.org/majordomo-info.html > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-mmc" > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo > > info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
