<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:10pt"><div><span><font size="2">></font></span><span style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; ">That makes the dirty_ratio even higher than when on battery. The </span><br></div><div style="font-size: 10pt; font-family: arial, helvetica, sans-serif; "><div style="font-size: 12pt; font-family: 'times new roman', 'new york', times, serif; ">>purpose of tuning these is to allow a laptop on battery to be more <br>>aggressive about keeping dirty pages in the cache and letting the disk <br>>stay asleep. Normally you want dirty pages to be flushed to disk fairly <br>>quickly.<br><br>>I'm curious if the normal value of 5 for background ratio but just <br>>increasing dirty_ratio to 20 or 25 would have a similar effect on your <br>>performance trouble without going to an
excess.<br><br>>Also if anything, increasing dirty_ratio should make swapping worse, not <br>>better, since more ram will be tied up in dirty cache pages. Are you <br>>sure you have a problem with swapping and not just applications blocking <br>>while writing data to disk?<br><br>You're right. I was playing with vfs_cache_pressure too and forgot to return it to default value of 100. That's what probably did the trick.</div><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;" class="yui_3_2_0_20_133538724631861">Anyway changing vfs_cache_pressure to 700 made 12.04 stop trashing with just a few large applications open (Ubuntu Software Center apears to be very resource intensive).</div><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;" class="yui_3_2_0_20_133538724631861"><br></div><div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"
class="yui_3_2_0_20_133538724631861"> <br><br> </div> </div> </div></body></html>