Hi Manoj, On Tue, Jul 12 2011, Manoj Iyer wrote: > Test System: ThinkPad X220 Tablet, using Sandisk 2GB Class 2 SD, I did > not see any considerable change in read/write times. Also, tested a > Transcend MMCPlus 2GB card, before the patch was applied it would not > mount the card, and would cause IO errors on read/write, but after the > patch it mounts and works correctly. > [..] > ============ BEFORE THE PATCH =============== > Sandisk 2GB Class2 SD > ============================================= > === WRITE === > u@u:~$ ls -lh test.file > -rw-r--r-- 1 u u 10M 2011-07-12 10:19 test.file > u@u:~$ time cp test.file /media/E0FD-1813/copyto > > real 0m0.480s > user 0m0.000s > sys 0m0.024s > [..] > ============ AFTER THE PATCH ============= > Sandisk 2GB Class2 SD > ========================================== > > === WRITE === > u@u:~$ time cp ./test.file /media/E0FD-1813/copyto1 > > real 0m0.757s > user 0m0.000s > sys 0m0.044s This suggests that there *was* a considerable difference in write speed, no? It might be helpful to use Arnd's flashbench tool¹ for further benchmarking, since it does the right thing with using direct I/O access without caches. Thanks, - Chris. ¹: http://git.linaro.org/gitweb?p=people/arnd/flashbench.git -- Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/> One Laptop Per Child -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
