On (22/10/25 13:30), Sergey Senozhatsky wrote:
> On (22/10/25 01:12), Sergey Senozhatsky wrote:
> > Sergey Senozhatsky (6):
> > zsmalloc: turn zspage order into runtime variable
> > zsmalloc/zram: pass zspage order to zs_create_pool()
> > zram: add pool_page_order device attribute
> > Documentation: document zram pool_page_order attribute
> > zsmalloc: break out of loop when found perfect zspage order
> > zsmalloc: make sure we select best zspage size
>
> Andrew, I want to replace the last 2 patches in the series: I think
> we can drop `usedpc` calculations and instead optimize only for `waste`
> value. Would you prefer me to resend the entire instead?
Andrew, let's do it another way - let's drop the last patch from the
series. But only the last one. The past was a last minute addition to
the series and I have not fully studied it's impact yet. From a
preliminary research I can say that it improves zsmalloc memory usage
only for order 4 zspages and has no statistically significant impact
on order 2 nor order 3 zspages.
Synthetic test, base get_pages_per_zspage() vs 'waste' optimized
get_pages_per_zspage() for order 4 zspages:
x zram-order-4-memused-base
+ zram-order-4-memused-patched
+----------------------------------------------------------------------------+
|+ + + + x xx x|
| |___________A_______M____| |____M_A______| |
+----------------------------------------------------------------------------+
N Min Max Median Avg Stddev
x 4 6.3960678e+08 6.3974605e+08 6.3962726e+08 6.3965082e+08 64101.637
+ 4 6.3902925e+08 6.3929958e+08 6.3926682e+08 6.3919514e+08 120652.52
Difference at 95.0% confidence
-455680 +/- 167159
-0.0712389% +/- 0.0261329%
(Student's t, pooled s = 96607.6)
If I will have enough confidence in that patch I will submit it
separately, with a proper commit message and clear justification.
