From: Andrii Anisov <andrii.anisov@gmail.com> To: xen-devel@lists.xenproject.org Cc: Julien Grall <julien.grall@arm.com>, Stefano Stabellini <sstabellini@kernel.org>, Andrii Anisov <andrii_anisov@epam.com> Subject: [PATCH v2] gic: drop interrupts enabling on interrupts processing Date: Mon, 27 May 2019 12:29:30 +0300 [thread overview] Message-ID: <1558949370-14331-1-git-send-email-andrii.anisov@gmail.com> (raw) From: Andrii Anisov <andrii_anisov@epam.com> This reduces the number of context switches in case we have coming guest interrupts from different sources at a high rate. What is likely for multimedia use-cases. Having irqs unlocked here makes us go through trap path again in case we have a new guest interrupt arrived (even with the same priority, after `desc->handler->end(desc)` in `do_IRQ()`), what is just a processor cycles wasting. We will catch them all in the `gic_interrupt() function loop anyway. And the guest irqs arrival prioritization is meaningless here, it is only effective at guest's level. Signed-off-by: Andrii Anisov <andrii_anisov@epam.com> --- Changes: in v2: Drop irq enabling for lpi processing as well. --- xen/arch/arm/gic.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index 6cc7dec..113655a 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -386,17 +386,13 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq) if ( likely(irq >= 16 && irq < 1020) ) { - local_irq_enable(); isb(); do_IRQ(regs, irq, is_fiq); - local_irq_disable(); } else if ( is_lpi(irq) ) { - local_irq_enable(); isb(); gic_hw_ops->do_LPI(irq); - local_irq_disable(); } else if ( unlikely(irq < 16) ) { -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: Andrii Anisov <andrii.anisov@gmail.com> To: xen-devel@lists.xenproject.org Cc: Julien Grall <julien.grall@arm.com>, Stefano Stabellini <sstabellini@kernel.org>, Andrii Anisov <andrii_anisov@epam.com> Subject: [Xen-devel] [PATCH v2] gic: drop interrupts enabling on interrupts processing Date: Mon, 27 May 2019 12:29:30 +0300 [thread overview] Message-ID: <1558949370-14331-1-git-send-email-andrii.anisov@gmail.com> (raw) Message-ID: <20190527092930.KviQ_QX34IXUo87A94-0uDZ_MfkzT7GCQwYG5CzhqX0@z> (raw) From: Andrii Anisov <andrii_anisov@epam.com> This reduces the number of context switches in case we have coming guest interrupts from different sources at a high rate. What is likely for multimedia use-cases. Having irqs unlocked here makes us go through trap path again in case we have a new guest interrupt arrived (even with the same priority, after `desc->handler->end(desc)` in `do_IRQ()`), what is just a processor cycles wasting. We will catch them all in the `gic_interrupt() function loop anyway. And the guest irqs arrival prioritization is meaningless here, it is only effective at guest's level. Signed-off-by: Andrii Anisov <andrii_anisov@epam.com> --- Changes: in v2: Drop irq enabling for lpi processing as well. --- xen/arch/arm/gic.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index 6cc7dec..113655a 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -386,17 +386,13 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq) if ( likely(irq >= 16 && irq < 1020) ) { - local_irq_enable(); isb(); do_IRQ(regs, irq, is_fiq); - local_irq_disable(); } else if ( is_lpi(irq) ) { - local_irq_enable(); isb(); gic_hw_ops->do_LPI(irq); - local_irq_disable(); } else if ( unlikely(irq < 16) ) { -- 2.7.4 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
next reply other threads:[~2019-05-27 9:29 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-27 9:29 Andrii Anisov [this message] 2019-05-27 9:29 ` [Xen-devel] [PATCH v2] gic: drop interrupts enabling on interrupts processing Andrii Anisov 2019-05-28 17:07 ` Julien Grall 2019-05-28 17:07 ` [Xen-devel] " Julien Grall 2019-05-29 10:31 ` Andrii Anisov 2019-05-29 10:31 ` [Xen-devel] " Andrii Anisov 2019-05-29 15:32 ` Julien Grall 2019-05-29 15:32 ` [Xen-devel] " Julien Grall 2019-05-30 16:12 ` Andrii Anisov 2019-05-30 16:12 ` [Xen-devel] " Andrii Anisov 2019-05-31 17:11 ` Julien Grall 2019-05-31 17:11 ` [Xen-devel] " Julien Grall 2019-05-31 20:08 ` Stefano Stabellini 2019-05-31 20:08 ` [Xen-devel] " Stefano Stabellini 2019-06-10 15:49 ` Andrii Anisov 2019-06-10 19:51 ` Julien Grall 2019-06-11 7:38 ` Andrii Anisov 2019-05-30 16:14 ` Andrii Anisov 2019-05-30 16:14 ` [Xen-devel] " Andrii Anisov 2019-05-31 17:16 ` Julien Grall 2019-05-31 17:16 ` [Xen-devel] " Julien Grall 2019-05-31 17:28 ` Andre Przywara 2019-05-31 17:28 ` [Xen-devel] " Andre Przywara 2019-05-31 17:25 ` Andre Przywara 2019-05-31 17:25 ` [Xen-devel] " Andre Przywara 2019-05-31 17:54 ` Julien Grall 2019-05-31 17:54 ` [Xen-devel] " Julien Grall
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