On (01/29/15 15:35), Minchan Kim wrote:
>
> As you told, the data was not stable.
>
yes. fread test was always slower, and the rest was mostly slower.
> Anyway, when I read down_read implementation, it's one atomic instruction.
> Hmm, it seems te be better for srcu_read_lock which does more things.
>
srcu looks havier, agree.
> But I guessed most of overhead are from [de]compression, memcpy, clear_page
> That's why I guessed we don't have measurable difference from that.
> What's the data pattern if you use iozone?
by "data pattern" you mean usage scenario? well, I usually use zram for
`make -jX', where X=[4..N]. so N concurrent read-write ops scenario.
-ss
> I guess it's really simple pattern compressor can do fast. I used /dev/sda
> for dd write so more realistic data. Anyway, if we has 10% regression even if
> the data is simple, I never want to merge it.
> I will test it carefully and if it turns out lots regression,
> surely, I will not go with this and send the original patch again.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
