Root Feeling adventurous? Got an experiment for you

I'm trying 384 already.

Google set this parameter with the advent of Froyo.

I think that it's become stale as a sacred cow.

Things have changed since then.

Although it's counterintuitive, for me this has left me with more free ram, faster scrolling everywhere, more web pages remaining stable (not going blank when not the visible page), much faster screen refreshes on blanked web pages, faster page loads, my gallery is just tons snappier, and - and this is really interesting - faster and smoother video watching on my usual anime and movies. Not sure how to describe that last bit, so I went with "faster" - like I may not have been consciously aware of lost frames - but playback is better.


Hmmmm. I ought to profile and see if it makes a difference in video recording...

Your first boot after the change will be longer while Dalvik adjusts.

What rom (and version) are you on?

Did you go with the 320 setting or jump straight to 384?

We need to get as many testing as possible.

With luck, assuming that everything continues to check out, I'll visit xda and see about getting this baked into a favorite rom.

I can't tell but I think that 320 384 might be better (with Viper4G).

Hah, now to retest everything.

Don't know what Moto was thinking, 32 is a silly value for that param.

I think that 384, while maybe a hair less quick than 320, is leaving things a little less - I don't know - jumpy?

About to clean wipe and test it from the top.

With a little help from google to save me typing the next few sentences...

(SHared Memory MAXimum) a configurable kernel parameter that defines the system-wide maximum allowable shared memory.

It's really the maximum size of any shared memory chunk.

SHMMAX is the maximum size of a single shared memory segment set in bytes.

The SHMMAX parameter is a safeguard parameter that sets the upper limit of how much shared memory a process can possibly request. The maximum supported value of SHMMAX on a 32-bit system is 4 GB - 1 byte.

Click to expand...

So far, increasing it above the 256 MB default, especially with Sense - made no sense just looking at it.

However - Google set this back in Froyo and HTC has used it since then.

Given that we were using it on an original Evo with only a small fraction ram compared to this - it started to make less sense to me - so I started tinkering.

What it's actually doing -

It seems that it is reducing the amount of the memory being held up by the kernel and shifting that into apps, both in the system space and user space.

And then that app memory is getting managed by the Android mechanisms we've discussed so often as the reason to avoid task killers.

With a net result of more things running with less ram used.

Why is it reducing the amount of kernel memory used?

I have no freaking clue.

It was making me crazy, I rather expected the exact opposite to happen - so I decided to not care and just focus on observables for a little while.

Shows that I've not looked at the kernel source tree in months - I tend to forget.

In any case - I'm still testing...

I can say that I have initially - possibly - maybe - great results with nav and Viper4G using 384.

However - that may well be at a cost where I'm breaking things and not seeing them yet.

It sure makes things scream.

It also completely trashed and broke my statusbar in one configuration so far - so - like most everything at this juncture - it's a not a magic silver bullet.

But -

1. It's really doing no actual harm.

2. Y'all made a nandroid if things get really bad.

Btw, I've been hating Boat Browser lately for causing panics in ICS.

If going to 384 hurts and you're using Boat, maybe don't for a bit.

Might have been Boat crashing my status bar.

The warning about experiment and broken stuff is because with this stuff, I'm conservative rather than OMGZ!! PWNIES!!!! with mods.

But if this hangs together, I'm fixing to get excited.

I've been held back on ICS because nav issues were not an option for me.

Despite the many with no nav issues I have yet to see a Jellybean rom here with zero nav issues.

And I have been running nav here for over an hour while loading up other stuff.

With no issues that I can see.

The testing continues...

Not yet, let us know.

Granite, are you on Viper4G?