Messages in this thread | | | Date | Tue, 07 Mar 2006 13:15:46 -0800 | From | Linda Walsh <> | Subject | Re: Readahead value 128K? (was Re: Drastic Slowdown of 'fseek()' Calls From 2.4 to 2.6 -- VMM Change?) |
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Marr wrote: > On Sunday 05 March 2006 6:02pm, Linda Walsh wrote: >> Does this happen with a seek call as well, or is this limited >> to fseek? >> >> if you look at "hdparm's" idea of read-ahead, what does it say >> for the device?. I.e.: >> >> hdparm /dev/hda: >> >> There is a line entitled "readahead". What does it say? > > Linda, > > I don't know (based on your email addressing) if you were directing this > question at me, but since I'm the guy who originally reported this issue, > here are my 'hdparm' results on my (standard Slackware 10.2) ReiserFS > filesystem: > > 2.6.13 (with 'nolargeio=1' for reiserfs mount): > readahead = 256 (on) > > 2.6.13 (without 'nolargeio=1' for reiserfs mount): > readahead = 256 (on) > > 2.4.31 ('nolargeio' option irrelevant/unavailable for 2.4.x): > readahead = 8 (on) > > *** Please CC: me on replies -- I'm not subscribed. > > Regards, > Bill Marr -------- Could you retry your test with read-ahead set to a smaller value? Say the same as in 2.4 (8) or 16 and see if that changes anything?
hdparm -a8 /dev/hdx or hdparm -a16 /dev/hdx
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