Messages in this thread | | | Subject | Re: [RFC PATCH] locking/percpu-rwsem: use this_cpu_{inc|dec}() for read_count | From | Boaz Harrosh <> | Date | Thu, 17 Sep 2020 16:46:38 +0300 |
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On 17/09/2020 15:48, Matthew Wilcox wrote: > On Thu, Sep 17, 2020 at 02:01:33PM +0200, Oleg Nesterov wrote: <> > > If we change bio_endio to invoke the ->bi_end_io callbacks in softirq > context instead of hardirq context, we can change the pagecache to take > BH-safe locks instead of IRQ-safe locks. I believe the only reason the > lock needs to be IRQ-safe is for the benefit of paths like: >
From my totally subjective experience on the filesystem side (user of bio_endio) all HW block drivers I used including Nvme isci, sata... etc. end up calling bio_endio in softirq. The big exception to that is the vdX drivers under KVM. Which is very Ironic to me. I wish we could make all drivers be uniform in this regard.
But maybe I'm just speaking crap. Its only from my limited debuging expirience.
Thanks Boaz
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