From: Pratyush Anand <panand@redhat.com> To: Jungseok Lee <jungseoklee85@gmail.com> Cc: catalin.marinas@arm.com, will.deacon@arm.com, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, takahiro.akashi@linaro.org, mark.rutland@arm.com, barami97@gmail.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/2] arm64: Introduce IRQ stack Date: Thu, 8 Oct 2015 15:55:20 +0530 [thread overview] Message-ID: <20151008102520.GA10912@dhcppc13.redhat.com> (raw) In-Reply-To: <1444231692-32722-2-git-send-email-jungseoklee85@gmail.com> Hi Jungseok, On 07/10/2015:03:28:11 PM, Jungseok Lee wrote: > Currently, kernel context and interrupts are handled using a single > kernel stack navigated by sp_el1. This forces a system to use 16KB > stack, not 8KB one. This restriction makes low memory platforms suffer > from memory pressure accompanied by performance degradation. How will it behave on 64K Page system? There, it would take atleast 64K per cpu, right? > +int alloc_irq_stack(unsigned int cpu) > +{ > + void *stack; > + > + if (per_cpu(irq_stacks, cpu).stack) > + return 0; > + > + stack = (void *)__get_free_pages(THREADINFO_GFP, THREAD_SIZE_ORDER); Above would not compile for 64K pages as THREAD_SIZE_ORDER is only defined for non 64K. This need to be fixed. ~Pratyush
WARNING: multiple messages have this Message-ID (diff)
From: panand@redhat.com (Pratyush Anand) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 1/2] arm64: Introduce IRQ stack Date: Thu, 8 Oct 2015 15:55:20 +0530 [thread overview] Message-ID: <20151008102520.GA10912@dhcppc13.redhat.com> (raw) In-Reply-To: <1444231692-32722-2-git-send-email-jungseoklee85@gmail.com> Hi Jungseok, On 07/10/2015:03:28:11 PM, Jungseok Lee wrote: > Currently, kernel context and interrupts are handled using a single > kernel stack navigated by sp_el1. This forces a system to use 16KB > stack, not 8KB one. This restriction makes low memory platforms suffer > from memory pressure accompanied by performance degradation. How will it behave on 64K Page system? There, it would take atleast 64K per cpu, right? > +int alloc_irq_stack(unsigned int cpu) > +{ > + void *stack; > + > + if (per_cpu(irq_stacks, cpu).stack) > + return 0; > + > + stack = (void *)__get_free_pages(THREADINFO_GFP, THREAD_SIZE_ORDER); Above would not compile for 64K pages as THREAD_SIZE_ORDER is only defined for non 64K. This need to be fixed. ~Pratyush
next prev parent reply other threads:[~2015-10-08 10:25 UTC|newest] Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-10-07 15:28 [PATCH v4 0/2] arm64: Introduce IRQ stack Jungseok Lee 2015-10-07 15:28 ` Jungseok Lee 2015-10-07 15:28 ` [PATCH v4 1/2] " Jungseok Lee 2015-10-07 15:28 ` Jungseok Lee 2015-10-08 10:25 ` Pratyush Anand [this message] 2015-10-08 10:25 ` Pratyush Anand 2015-10-08 14:32 ` Jungseok Lee 2015-10-08 14:32 ` Jungseok Lee 2015-10-08 16:51 ` Pratyush Anand 2015-10-08 16:51 ` Pratyush Anand 2015-10-07 15:28 ` [PATCH v4 2/2] arm64: Expand the stack trace feature to support " Jungseok Lee 2015-10-07 15:28 ` Jungseok Lee 2015-10-09 14:24 ` James Morse 2015-10-09 14:24 ` James Morse 2015-10-12 14:53 ` Jungseok Lee 2015-10-12 14:53 ` Jungseok Lee 2015-10-12 16:34 ` James Morse 2015-10-12 16:34 ` James Morse 2015-10-12 22:13 ` Jungseok Lee 2015-10-12 22:13 ` Jungseok Lee 2015-10-13 11:00 ` James Morse 2015-10-13 11:00 ` James Morse 2015-10-13 15:00 ` Jungseok Lee 2015-10-13 15:00 ` Jungseok Lee 2015-10-14 12:12 ` Jungseok Lee 2015-10-14 12:12 ` Jungseok Lee 2015-10-15 15:59 ` James Morse 2015-10-15 15:59 ` James Morse 2015-10-16 13:01 ` Jungseok Lee 2015-10-16 13:01 ` Jungseok Lee 2015-10-16 16:06 ` Catalin Marinas 2015-10-16 16:06 ` Catalin Marinas 2015-10-17 13:38 ` Jungseok Lee 2015-10-17 13:38 ` Jungseok Lee 2015-10-19 16:18 ` Catalin Marinas 2015-10-19 16:18 ` Catalin Marinas 2015-10-20 13:08 ` Jungseok Lee 2015-10-20 13:08 ` Jungseok Lee 2015-10-21 15:14 ` Jungseok Lee 2015-10-21 15:14 ` Jungseok Lee 2015-10-14 7:13 ` AKASHI Takahiro 2015-10-14 7:13 ` AKASHI Takahiro 2015-10-14 12:24 ` Jungseok Lee 2015-10-14 12:24 ` Jungseok Lee 2015-10-14 12:55 ` Jungseok Lee 2015-10-14 12:55 ` Jungseok Lee 2015-10-15 4:19 ` AKASHI Takahiro 2015-10-15 4:19 ` AKASHI Takahiro 2015-10-15 13:39 ` Jungseok Lee 2015-10-15 13:39 ` Jungseok Lee 2015-10-19 6:47 ` AKASHI Takahiro 2015-10-19 6:47 ` AKASHI Takahiro 2015-10-20 13:19 ` Jungseok Lee 2015-10-20 13:19 ` Jungseok Lee 2015-10-15 14:24 ` Jungseok Lee 2015-10-15 14:24 ` Jungseok Lee 2015-10-15 16:01 ` James Morse 2015-10-15 16:01 ` James Morse 2015-10-16 13:02 ` Jungseok Lee 2015-10-16 13:02 ` Jungseok Lee
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