On Sun, Sep 25, 2011 at 11:54:28PM -0700, Eric Gouriou wrote: > This patch introduces a fast path in ext4_ext_convert_to_initialized() > for the case when the conversion can be performed by transferring > the newly initialized blocks from the uninitialized extent into > an adjacent initialized extent. Doing so removes the expensive > invocations of memmove() which occur during extent insertion and > the subsequent merge. > > In practice this should be the common case for clients performing > append writes into files pre-allocated via > fallocate(FALLOC_FL_KEEP_SIZE). In such a workload performed via > direct IO and when using a suboptimal implementation of memmove() > (x86_64 prior to the 2.6.39 rewrite), this patch reduces kernel CPU > consumption by 32%. > > Two new trace points are added to ext4_ext_convert_to_initialized() > to offer visibility into its operations. No exit trace point has > been added due to the multiplicity of return points. This can be > revisited once the upstream cleanup is backported. > > Signed-off-by: Eric Gouriou <egouriou@xxxxxxxxxx> Thanks, applied. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
