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Groups > linux.kernel > #1198834
| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff |
| Date | 2015-08-03 15:10 +0200 |
| Message-ID | <pTnF8-3WH-9@gated-at.bofh.it> (permalink) |
| References | <pTkQW-8kh-1@gated-at.bofh.it> <pTkQW-8kh-7@gated-at.bofh.it> <pTmzo-29E-17@gated-at.bofh.it> <pTnF8-3WH-11@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Aug 03, 2015 at 01:02:09PM +0000, Vineet Gupta wrote: > On Monday 03 August 2015 05:21 PM, Peter Zijlstra wrote: > > On Mon, Aug 03, 2015 at 03:33:07PM +0530, Vineet Gupta wrote: > > > > +#define SCOND_FAIL_RETRY_ASM \ > > + " bz 4f \n" \ > > + " ; --- scond fail delay --- \n" \ > > + " mov %[tmp], %[delay] \n" /* tmp = delay */ \ > > + "2: brne.d %[tmp], 0, 2b \n" /* while (tmp != 0) */ \ > > + " sub %[tmp], %[tmp], 1 \n" /* tmp-- */ \ > > + " asl %[delay], %[delay], 1 \n" /* delay *= 2 */ \ > > + " b 1b \n" /* start over */ \ > > + "4: ; --- success --- \n" \ > > > One more note, you might want a test to handle the case where delay *= 2 > overflows and results in a 0. > > > yeah ! > > - asl %[delay], %[delay], 1 > + asl.f %[delay], %[delay], 1 > + mov.z %[delay], 1 The other obvious option is: 0x80000000 :-) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH 0/6] ARC: spinlocks/atomics rework Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
[PATCH 4/6] ARC: LLOCK/SCOND based rwlock Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
Re: [PATCH 4/6] ARC: LLOCK/SCOND based rwlock Peter Zijlstra <peterz@infradead.org> - 2015-08-03 13:40 +0200
Re: [PATCH 4/6] ARC: LLOCK/SCOND based rwlock Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 14:00 +0200
[PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
Re: [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Peter Zijlstra <peterz@infradead.org> - 2015-08-03 13:50 +0200
Re: [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 16:50 +0200
Re: [PATCH 6/6] ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle Peter Zijlstra <peterz@infradead.org> - 2015-08-03 16:50 +0200
[PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Peter Zijlstra <peterz@infradead.org> - 2015-08-03 13:50 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 15:10 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 16:00 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Peter Zijlstra <peterz@infradead.org> - 2015-08-03 16:10 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Peter Zijlstra <peterz@infradead.org> - 2015-08-03 14:00 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Peter Zijlstra <peterz@infradead.org> - 2015-08-03 15:10 +0200
Re: [PATCH 5/6] ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 15:10 +0200
[PATCH 3/6] ARC: LLOCK/SCOND based spin_lock Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
Re: [PATCH 3/6] ARC: LLOCK/SCOND based spin_lock Peter Zijlstra <peterz@infradead.org> - 2015-08-03 13:30 +0200
Re: [PATCH 3/6] ARC: LLOCK/SCOND based spin_lock Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 13:50 +0200
[PATCH 1/6] Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock" Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
[PATCH 2/6] ARC: refactor atomic inline asm operands with symbolic names Vineet Gupta <Vineet.Gupta1@synopsys.com> - 2015-08-03 12:10 +0200
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