Messages in this thread | | | Subject | Re: [GIT PULL] Block fixes for 4.5-final | From | Jens Axboe <> | Date | Thu, 3 Mar 2016 14:28:50 -0700 |
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On 03/03/2016 02:20 PM, Linus Torvalds wrote: > On Thu, Mar 3, 2016 at 1:11 PM, Jens Axboe <axboe@fb.com> wrote: >> >> It does fix a regression - the change is that NVMe now uses the block layer >> for these types of requests, and they don't have to adhere to the regular fs >> limits of sizing. Hence we broke real use cases, of (for instance) pulling >> logs off devices. Both of the referenced commits were added yesterday, not >> today. And they should have been folded, but I had already committed the >> first one. I don't think that should preclude doing it much cleaner than the >> first one. > > Why does this affect only NVMe, and not all the other drivers that > have been around forever? What is that magical case that breaks? > Details, please.
Development around NVMe is a lot more active than any other driver. And that tends to drive a lot more testing, and find a lot of other bugs. That, and the fact that NVMe is still fairly young. On top of that, NVMe has been driving/utilizing some parts of blk-mq, and exercising things like surprise hot removal that haven't seen a ton of testing.
>> Fair enough, I can boil it down somewhat. But honestly, the only stuff I'd >> feel comfortable pulling out now would be the lightnvm changes which aren't >> that critical due to the user base, though that's also why it would be fine >> to shove it in now. And the cgroup writeback enable, which can wait. The two >> commits referenced above could be folded, but they'd still be in the new >> pull request. >> >> So let me know if you want that, or we can proceed with the current branch, >> because most of it should really go in as-is. > > I basically want for every commit an explanation of why it's so > critical by now. I want to make you have to *think* and explain before > you send stuff at this stage, and I want to understand why each commit > is so important. > > Because really, this has been going on far too long, and this pull > request looked singularly pointless. > > No way do I want things like cgroup writeback changes outside the > merge window, for example, unless it's a major performance regression > (with numbers) or something like that. > > No way do I want any lightnvm stuff. > > No way do I want big "cleanup" patches.
I'll boil it down.
-- Jens Axboe
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