Messages in this thread | | | Subject | Re: [f2fs-dev] [PATCH] f2fs: fix to correct freed section number during gc | From | Chao Yu <> | Date | Fri, 25 Sep 2015 20:43:57 +0800 |
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Hi Jaegeuk,
> On Sep 24, 2015, at 5:08 AM, Jaegeuk Kim <jaegeuk@kernel.org> wrote: > > Hi Chao, > > On Wed, Sep 23, 2015 at 06:11:36PM +0800, Chao Yu wrote: >> Hi Jaegeuk, >> >>> -----Original Message----- >>> From: Jaegeuk Kim [mailto:jaegeuk@kernel.org] >>> Sent: Wednesday, September 23, 2015 6:54 AM >>> To: Chao Yu >>> Cc: linux-f2fs-devel@lists.sourceforge.net; linux-kernel@vger.kernel.org >>> Subject: Re: [PATCH] f2fs: fix to correct freed section number during gc >>> >>> Hi Chao, >>> >>> On Tue, Sep 22, 2015 at 09:18:18PM +0800, Chao Yu wrote: >>>> We pass 'nfree' to has_not_enough_free_secs to check whether there is >>>> enough free section, but 'nfree' indicates the number of segment gced, >>>> should alter the value to section number. >>> >>> Yeah, but I think we need to increase nfree only when an entire section is gced >>> completely, since sometimes nfree can be increased across sections. >> >> Agree, I will fix that. >> >> Still have one question, for foreground gc, why would we give up retry writing >> out pages of last victim, but trying to select another victim for cleanup? >> Will new introduced method cause long latency for caller than before? > > Hmm. Very occasionally, I've seen that gc goes into an infinite loop to clean up > one victim. In order to avoid that, I added giving up and then doing gc again. > I think there is no problem in normal cases. Even in an abnormal case, I expect > that next victim would be selected again because that should have lowest moving > cost.
Got it, thanks for your explanation! :)
I have sent the v2 patch, please help to review.
Thanks,
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