Then setup a test system which will reproduce hitting this corner case and instrument your code to see is there's any gain at all. On Tue, Aug 26, 2014 at 4:14 PM, Nick <xerofoify@xxxxxxxxx> wrote: > > > On 08/26/2014 06:58 PM, Mandeep Sandhu wrote: >> If it's a corner case, it won't be hit often enough right? And if it >> was hit often enough, it wouldn't be corner case!? :) >> >> These 2 are mutually exclusive! >> >> >> On Tue, Aug 26, 2014 at 3:47 PM, Nick <xerofoify@xxxxxxxxx> wrote: >>> After reading through the code in inode.c today , I am curious about the comment and the following code I will paste >>> below. I am curious if this corner case is hit often enough for me to write a patch to improve the speed of this >>> corner case. Furthermore , compress_file_range is the function name, in case you can't guess by the pasted code. >>> Regards Nick >>> 411 /* >>> 412 * we don't want to send crud past the end of i_size through >>> 413 * compression, that's just a waste of CPU time. So, if the >>> 414 * end of the file is before the start of our current >>> 415 * requested range of bytes, we bail out to the uncompressed >>> 416 * cleanup code that can deal with all of this. >>> 417 * >>> 418 * It isn't really the fastest way to fix things, but this is a >>> 419 * very uncommon corner. >>> 420 */ >>> 421 if (actual_end <= start) >>> 422 goto cleanup_and_bail_uncompressed; >>> >>> _______________________________________________ >>> Kernelnewbies mailing list >>> Kernelnewbies@xxxxxxxxxxxxxxxxx >>> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > I get that my question is if this corner case is hit, enough for me to write a patch to optimize it. > In addition the comment states it isn't but want to known for standard compression workloads in btrfs > if it's hit enough for me to work on this and how much speed degradation are me we doing my not writing > it better. > Nick _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
