boot error
 

My Thinkpad X200 has been running Slackware64 perfectly up until the last few boots, when it's developed the problem shown in the attachment. As suggested at the bottom of the screen, a reboot fixes it - 'til next boot. A brief websearch revealed bad RAM could be the cause, so I ran Memtest and it passed OK. Any ideas as to the cause and possible permanent fix?

Maybe be you use the Slackware-current?

No, it's 14.2. It's been on the X200 since I bought it (refurbished) nearly a year ago.

Sorry, but still looks as being some bad RAM, or you are so lucky to have some bad sector just at beginning of your SWAP.

BTW, you upgraded the kernel in the last times?

I'm on 4.4.88. I'll run Memtest again. Checking swap: do I run fsck /swap?

Running Memtest on it again.

Memtest Overnight
 

Some of the RAM problems I've had on laptops were only found by running memtest for a day or two. Running memtest for only a couple of hours didn't find the problem (possibly heat related).

IF you can easily access the RAM boards and there are more than one you could try reseating the boards, booting with only 1 board at a time, or swapping the location of the two boards.

You may also experiment with booting through a USB port or replacing the disk temporarily or run smartctl to see if it may be a disk issue. You may also want to reseat the disk/SSD.

Sometimes the hardware is good but there is just a bad "connection".

I don't have a Thinkpad X200 so I don't know how easy it is to access the hardware.

That's one good thing about Thinkpads: easy access to hardware.

Just tried those two options, and it booted up OK. I'll see what happens with the next two boots before I celebrate. :)
Thanks, both of you, for your help and suggestions.

How long does it run (each time), before the panic?
Is the "RIP" and stacktrace (mostly) the same each time, or (very) different?

Same time, same place, same message.

Still misbehaving. Looks like I'll have to buy it some new RAM for Christmas.

Does the output is after setting debug boot parameter? Is it your default boot? Boot kernel with default parameters (as set in lilo.conf)? Or have you enabled additional debug level? I want to know simply, may something like this will happen to me I would try to play with debugging boot process with means given by boot parameters. For curiosity. And because it is good to know things. But, well, luckily it is not now :(.

I looked around. Some people refer this as battery/power issue, or video. Some report booting live system ok. So maybe to try to boot any other kernel, from usb, or CD?

Thanks, igadoter, I'll look into setting debug parameters.

I'll give Memtest another go, let it run for a longer time, as TracyTiger suggested, just to find out if the problem is with the RAM or not.