Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!nx01.iad01.newshosting.com!newshosting.com!69.16.185.16.MISMATCH!npeer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!postnews.google.com!b34g2000prf.googlegroups.com!not-for-mail From: Ripunjay Tripathi Newsgroups: comp.os.linux.development.system Subject: Significance of SoftIRQs and Tasklets Date: Sun, 21 Aug 2011 08:55:21 -0700 (PDT) Organization: http://groups.google.com Lines: 22 Message-ID: NNTP-Posting-Host: 14.96.168.87 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: posting.google.com 1313942355 3769 127.0.0.1 (21 Aug 2011 15:59:15 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sun, 21 Aug 2011 15:59:15 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: b34g2000prf.googlegroups.com; posting-host=14.96.168.87; posting-account=Es_fVwoAAAB-Y4IoD55tNN-Obl4IeNNA User-Agent: G2/1.0 X-Google-Web-Client: true X-Google-Header-Order: HUALESNKRC X-HTTP-UserAgent: Mozilla/5.0 (Windows NT 6.1; rv:6.0) Gecko/20100101 Firefox/6.0,gzip(gfe) Xref: x330-a1.tempe.blueboxinc.net comp.os.linux.development.system:251 While studying Linux interrupt handling I found that Tasklets and SoftIRQs are two different methods of performing "bottom half" (lesser priority work). I understand this (quite genuine need). Difference being, SoftIRQs are re-entarant while a Tasklet is NOT. That same SoftIRQ can run on different CPUs while this is NOT the case with Tasklets. Though I understand this from surface but I fail in understanding the requirements of the two features. In what case(s) we may use these facilities ? Also what do we mean by Tasklets are made upon SoftIRQs ? In one of the books I read, in LKML there were debates upon removing Tasklets. I got completely confused why one would bring in such a feature ? Some shortsightedness (No offense meant) ? Any pointers on this will help a lot. Thanks for your time :) Ripunjay Tripathi