so zorin os for me uses 3gb ram on idle, i was working on some things for a few hours, had 2 dozen tabs open, few pdfs, few odt files, sticky notes, whatsapp, outlook open, nothing too crazy, i have 16gb ram btw, but it showed 15gb ram used, and when i closed everything, it was still showing 10-11gb ram used???? i used disk flushing command but that took away 1gb-ish, it was still using 10gb ram, yes i used the free -m command, and it showed i only have few gb left, even that stated that 10+gb ram is being used on idle, i am very confused
system monitor "used" after closing apps is usually page cache. linux keeps file data in ram on purpose and will drop it when something else needs it.
check:
free -h
look at the available column, not just used. available is what you can actually give to new apps.
also in system monitor, expand memory and see how much is cache vs apps. dropping caches with drop_caches only "frees" reclaimable cache and isnt needed day to day.
if available is still tiny with everything closed, then look for a stuck process (look at the top mem rows) or a memory leak in one of the apps you had open. paste free -h after a fresh login with nothing open if you want a cleaner read.
i dont think its page cache, or if it is, its affecting the performance, because while using the laptop, my ram got maxed out, as shown in the image, swap began to be used while the workload was minimum and i could notice that things were opening a second too late, minor lags started to appear which should NOT be happening at all considering the actual work load. in system monitor i actually even checked the processes, and highest was abt 500mb, adding it all up(afterclosing the apps) was less than 2gb, while total ram usage was 10gb+
yeah free -h can look scary like that. in your screenshot Available was still about 5.5G while Used showed ~10G. that Available number is what new apps can take. the gap is mostly reclaimable cache/buffers that dont show as a single process.
when you hit max while working, that is different from the idle-after-close number. paste a fresh free -h and the top 10 from System Monitor → Processes sorted by Memory while it feels laggy (apps still open). if Available drops under ~1G with swap climbing, something real is leaking or you just had too much open at once.
yes 5.5gb is the available one, but i barely had anything open, 1-2 gb only, i normally have 12-13gb available ram when nothing is running, so theres a huge gap here that isnt being explained.
ok so rn i closed all my apps, ram usage fell to 5.6-6gb, still high. checked free -h only showed 9gb available which is still too low? it shows 12 ish gb normally, this is the yesterday problem but on a smaller scale, i guess it just grows over time.
that free -h looks healthy. Available 9.2G and swap at 0B. Used 5.6G after closing apps is higher than a fresh boot, yeah, but it is not the crisis the System Monitor bar makes it look like.
the bar and the process list often disagree because a chunk sits in kernel slab / unreclaimable pages / background services that dont show as one fat app. paste:
ps aux --sort=-%mem | head -20
grep -E 'MemAvailable|AnonPages|SReclaimable|SUnreclaim|Shmem|Cached' /proc/meminfo
if AnonPages is the big chunk, something user-space is still holding it (flatpak helpers, browser leftover, etc). if SUnreclaim is fat, that is kernel and usually only a reboot clears it.
yes its not a crisis, but i was showing, what happened to me the other day, the new screenshot shows that its starting to happen again, my guess is, over time this ram usage keeps on increasing somehow.
just took the screenshot, after a fresh startup, with 5 browser tabs open.(ram usage 5.3gb)
seems like anon pages is taking a good chunk, and Sunreclaim is small but i also just started it up, is it possible it was Sunreclaim causing the ram bloat? ig ill have to wait for this to happen again to confirm
even then, what processes is showing is far lesser than the total usage. i dont understand how my ram gets maxed out with just 3-4gb of brave and 1-2gb of other applications???
yeah AnonPages that high with only a few brave tabs usually means brave itself plus its helpers are holding more than the process list makes obvious. each tab plus gpu and renderer kids add up, and they dont always roll into one fat line in system monitor.
after a fresh boot, 5.3G with 5 tabs is a bit chunky but not weird for brave on gnome.
when it climbs toward max again, grab:
ps aux --sort=-%mem | head -25
and also:
smem -k -s rss | head -20
(if smem isnt installed: sudo apt install smem)
if brave rss is the pile, try brave://settings/system and turn hardware acceleration off for a bit, or cut down extra windows. gnome-software likes to stick after you close the window too, so kill it from system monitor if its near the top again.
