>>>>> Badari Pulavarty (BP) writes: BP> Sure. I think it will improve the allocation case. BP> Non-allocation case, should be pretty much same, provided BP> I got contiguous layout on the disk. Isn't it ?
not allocation only: [EMAIL PROTECTED] root]# time /work/tests/fwrite /test/fff 64 10000 real 0m13.102s user 0m0.027s sys 0m4.003s [EMAIL PROTECTED] root]# time /work/tests/fwrite /test/fff 64 10000 real 0m22.210s user 0m0.006s sys 0m3.241s [EMAIL PROTECTED] root]# time /work/tests/fwrite /test/fff 64 10000 real 0m23.242s user 0m0.005s sys 0m3.202s [EMAIL PROTECTED] root]# time /work/tests/fwrite /test/fff 64 10000 real 0m24.777s user 0m0.011s sys 0m3.175s I think at least couple things're involved: - for already allocated block I don't open a transaction - extents code caches last found extent, so most lookups just do few compares with in-inode integers and don't walk though a tree btw, I've observed the following issue: sometimes vm can run several ->writepages() against a same file or mix ->writepages() with ->writepage(). I think this can break layout ... thanks, Alex - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
