Re: arc_usr_cmpxchg and preemption

> On Thu, Mar 15, 2018 at 12:03 PM, Alexey Brodkin > wrote: > Here's a brief analysis: > ARM: Looks like they got rid of that stuff in v4.4, see > commit db695c0509d6 ("ARM: remove user cmpxchg syscall"). > > M68K: That's even uglier implementation which is really asking for > a face

Re: arc_usr_cmpxchg and preemption

Hi Peter, Vineet, On Wed, 2018-03-14 at 18:53 +0100, Peter Zijlstra wrote: > On Wed, Mar 14, 2018 at 09:58:19AM -0700, Vineet Gupta wrote: > > > Well it is broken wrt the semantics the syscall is supposed to provide. > > Preemption disabling is what prevents a concurrent thread from coming in and

Re: arc_usr_cmpxchg and preemption

On Fri, Mar 16, 2018 at 10:54:52AM -0700, Vineet Gupta wrote: > I'd say just bite the bullet, write the patch and we can refine it there ! Just be glad its not futex.c proper ;-) I'll try and have a look later.. ___ linux-snps-arc mailing list linux-snp

Re: arc_usr_cmpxchg and preemption

On 03/16/2018 10:33 AM, Alexey Brodkin wrote: Hi Peter, Vineet, On Wed, 2018-03-14 at 18:53 +0100, Peter Zijlstra wrote: On Wed, Mar 14, 2018 at 09:58:19AM -0700, Vineet Gupta wrote: Well it is broken wrt the semantics the syscall is supposed to provide. Preemption disabling is what prevents

Re: mmc: block: bonnie++ runs with errors on arc/hsdk board

Hello Adrian, > Yes.  Unfortunately the clock used is not accurate enough to correctly order > the events across different CPUs, which makes it very hard to see delays > between requests.  You could try a different clock - refer the --clockid > option to perf record. > > Nevertheless it shows the

Re: Do we need to disable preemption in flush_tlb_range()?

Hi Peter, On Fri, 2018-03-16 at 11:11 +0100, Peter Zijlstra wrote: > On Thu, Mar 15, 2018 at 09:39:31AM +, Alexey Brodkin wrote: > > Hi Peter, > > > > On Thu, 2018-03-15 at 09:27 +0100, Peter Zijlstra wrote: > > > On Wed, Mar 14, 2018 at 01:19:01PM -0700, Vineet Gupta wrote: > > > > +CC Peter

Re: mmc: block: bonnie++ runs with errors on arc/hsdk board

On 15/03/18 17:08, Evgeniy Didin wrote: > Hi Adrian, > >> On 14/03/18 14:32, Evgeniy Didin wrote: >>> Hi Adrian, > > Was the performance affected? i.e. the results from bonnie++ I have run bonnie++ several times before and after mentioned commit. Here is output: --

Re: Do we need to disable preemption in flush_tlb_range()?

On Thu, Mar 15, 2018 at 09:39:31AM +, Alexey Brodkin wrote: > Hi Peter, > > On Thu, 2018-03-15 at 09:27 +0100, Peter Zijlstra wrote: > > On Wed, Mar 14, 2018 at 01:19:01PM -0700, Vineet Gupta wrote: > > > +CC Peter since we have his attention ;-) > > > > Yeah, timezone collision there, I typi

Re: arc_usr_cmpxchg and preemption

On Thu, Mar 15, 2018 at 07:03:32PM +, Alexey Brodkin wrote: > > I think there's a bunch of architectures that are in the same boat. > > m68k, arm, mips was mentioned. Sure, the moment an arch has hardware > > support you don't need the syscall anymore. > > Here's a brief analysis: > ARM: Look

Re: [PATCH] mmc: dw_mmc: fix falling from idmac to PIO mode when dw_mci_reset occurs

On 15 March 2018 at 18:24, Evgeniy Didin wrote: > On Thu, 2018-03-15 at 14:39 +0100, Ulf Hansson wrote: >> On 15 March 2018 at 14:18, Evgeniy Didin wrote: >> > Hello Ulf, >> > >> > On Thu, 2018-03-15 at 10:57 +0100, Ulf Hansson wrote: >> > > On 14 March 2018 at 20:30, Evgeniy Didin >> > > wrote

Re: mmc: block: bonnie++ runs with errors on arc/hsdk board

On 15/03/18 19:21, Alexey Brodkin wrote: > Hi Vineet, > > On Thu, 2018-03-15 at 09:38 -0700, Vineet Gupta wrote: >> On 03/15/2018 02:27 AM, Adrian Hunter wrote: >>> Please try: >>> >>> perf record -a -e mmc:* -- bonnie++ -u root -r 256 -s 512 -x 1 -d /mnt >>> >>> and share the resulting perf.d