From: "Serge E. Hallyn" <serue@us.ibm.com> To: Christoffer Dall <christofferdall@christofferdall.dk> Cc: containers <containers@lists.linux-foundation.org>, linux-arm-kernel <linux-arm-kernel@lists.infradead.org>, linux-kernel <linux-kernel@vger.kernel.org>, rmk@arm.linux.org.uk Subject: Re: [C/R ARM][PATCH 3/3] c/r: ARM implementation of checkpoint/restart Date: Tue, 23 Mar 2010 11:09:33 -0500 [thread overview] Message-ID: <20100323160933.GA4465@us.ibm.com> (raw) In-Reply-To: <1269219965-23923-4-git-send-email-christofferdall@christofferdall.dk> Quoting Christoffer Dall (christofferdall@christofferdall.dk): > Implements architecture specific requirements for checkpoint/restart on > ARM. The changes touch almost only c/r related code. Most of the work is > done in arch/arm/checkpoint.c, which implements checkpointing of the CPU > and necessary fields on the thread_info struct. > > The ISA version (given by __LINUX_ARM_ARCH__) is checkpointed and verified > against the machine architecture on restart. If they differ, an error is > raised and restart aborted. It should be possible to restart on newer > architectures, but further investigation is warranted. > > Regarding ThumbEE, the thumbee_state field on the thread_info is stored > in checkpoints when CONFIG_ARM_THUMBEE and 0 is stored otherwise. If > a value different than 0 is checkpointed and CONFIG_ARM_THUMBEE is not > set on the restore system, the restore is aborted. Feedback on this > implementation is very welcome. > > We checkpoint whether the system is running with CONFIG_MMU or not and > require the same configuration for the system on which we restore the > process. It might be possible to allow something more fine-grained, > if it's worth the energy. Input on this item is also very welcome, > specifically from someone who knows the exact meaning of the end_brk > field. > > Added support for syscall sys_checkpoint and sys_restart for ARM: > __NR_checkpoint 367 > __NR_restart 368 > > > Cc: rmk@arm.linux.org.uk > Signed-off-by: Christoffer Dall <christofferdall@christofferdall.dk> > Acked-by: Oren Laadan <orenl@cs.columbia.edu> In terms of the cr api I don't see any problems. Two nits below, but in any case Acked-by: Serge Hallyn <serue@us.ibm.com> thanks, this is really cool, especially how minimal it is :) -serge ... > +static int load_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t) > +{ > + int i; > + struct pt_regs *regs = task_pt_regs(t); > + > + memcpy(regs, &h->uregs, sizeof(struct pt_regs)); > + > + for (i = 0; i < 16; i++) > + regs->uregs[i] = h->uregs[i]; > + > + /* > + * Restore only user-writable bits on the CPSR > + */ > + regs->ARM_cpsr = regs->ARM_cpsr | > + (h->ARM_cpsr & (PSR_N_BIT | PSR_Z_BIT | > + PSR_C_BIT | PSR_V_BIT | > + PSR_V_BIT | PSR_Q_BIT | > + PSR_E_BIT | PSR_GE_BITS)); > + regs->ARM_ORIG_r0 = h->ARM_ORIG_r0; > + > + return 0; > +} > + > +/* read the cpu state and registers for the current task */ > +int restore_cpu(struct ckpt_ctx *ctx) > +{ > + struct ckpt_hdr_cpu *h; > + struct task_struct *t = current; > + int ret; > + > + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_CPU); > + if (IS_ERR(h)) > + return PTR_ERR(h); > + > + ret = load_cpu_regs(h, t); will load_cpu_regs() ever be changed to return anything but 0? If not both fns can be simplified. ... > +int restore_mm_context(struct ckpt_ctx *ctx, struct mm_struct *mm) > +{ > + struct ckpt_hdr_mm_context *h; > + int ret = 0; > + > + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_MM_CONTEXT); > + if (IS_ERR(h)) > + return PTR_ERR(h); > + > +#if !CONFIG_MMU > + mm->context.end_brk = h->end_brk; > +#endif > + > + ckpt_hdr_put(ctx, h); > + return ret; Again ret doesn't seem needed here. -serge
WARNING: multiple messages have this Message-ID (diff)
From: serue@us.ibm.com (Serge E. Hallyn) To: linux-arm-kernel@lists.infradead.org Subject: [C/R ARM][PATCH 3/3] c/r: ARM implementation of checkpoint/restart Date: Tue, 23 Mar 2010 11:09:33 -0500 [thread overview] Message-ID: <20100323160933.GA4465@us.ibm.com> (raw) In-Reply-To: <1269219965-23923-4-git-send-email-christofferdall@christofferdall.dk> Quoting Christoffer Dall (christofferdall at christofferdall.dk): > Implements architecture specific requirements for checkpoint/restart on > ARM. The changes touch almost only c/r related code. Most of the work is > done in arch/arm/checkpoint.c, which implements checkpointing of the CPU > and necessary fields on the thread_info struct. > > The ISA version (given by __LINUX_ARM_ARCH__) is checkpointed and verified > against the machine architecture on restart. If they differ, an error is > raised and restart aborted. It should be possible to restart on newer > architectures, but further investigation is warranted. > > Regarding ThumbEE, the thumbee_state field on the thread_info is stored > in checkpoints when CONFIG_ARM_THUMBEE and 0 is stored otherwise. If > a value different than 0 is checkpointed and CONFIG_ARM_THUMBEE is not > set on the restore system, the restore is aborted. Feedback on this > implementation is very welcome. > > We checkpoint whether the system is running with CONFIG_MMU or not and > require the same configuration for the system on which we restore the > process. It might be possible to allow something more fine-grained, > if it's worth the energy. Input on this item is also very welcome, > specifically from someone who knows the exact meaning of the end_brk > field. > > Added support for syscall sys_checkpoint and sys_restart for ARM: > __NR_checkpoint 367 > __NR_restart 368 > > > Cc: rmk at arm.linux.org.uk > Signed-off-by: Christoffer Dall <christofferdall@christofferdall.dk> > Acked-by: Oren Laadan <orenl@cs.columbia.edu> In terms of the cr api I don't see any problems. Two nits below, but in any case Acked-by: Serge Hallyn <serue@us.ibm.com> thanks, this is really cool, especially how minimal it is :) -serge ... > +static int load_cpu_regs(struct ckpt_hdr_cpu *h, struct task_struct *t) > +{ > + int i; > + struct pt_regs *regs = task_pt_regs(t); > + > + memcpy(regs, &h->uregs, sizeof(struct pt_regs)); > + > + for (i = 0; i < 16; i++) > + regs->uregs[i] = h->uregs[i]; > + > + /* > + * Restore only user-writable bits on the CPSR > + */ > + regs->ARM_cpsr = regs->ARM_cpsr | > + (h->ARM_cpsr & (PSR_N_BIT | PSR_Z_BIT | > + PSR_C_BIT | PSR_V_BIT | > + PSR_V_BIT | PSR_Q_BIT | > + PSR_E_BIT | PSR_GE_BITS)); > + regs->ARM_ORIG_r0 = h->ARM_ORIG_r0; > + > + return 0; > +} > + > +/* read the cpu state and registers for the current task */ > +int restore_cpu(struct ckpt_ctx *ctx) > +{ > + struct ckpt_hdr_cpu *h; > + struct task_struct *t = current; > + int ret; > + > + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_CPU); > + if (IS_ERR(h)) > + return PTR_ERR(h); > + > + ret = load_cpu_regs(h, t); will load_cpu_regs() ever be changed to return anything but 0? If not both fns can be simplified. ... > +int restore_mm_context(struct ckpt_ctx *ctx, struct mm_struct *mm) > +{ > + struct ckpt_hdr_mm_context *h; > + int ret = 0; > + > + h = ckpt_read_obj_type(ctx, sizeof(*h), CKPT_HDR_MM_CONTEXT); > + if (IS_ERR(h)) > + return PTR_ERR(h); > + > +#if !CONFIG_MMU > + mm->context.end_brk = h->end_brk; > +#endif > + > + ckpt_hdr_put(ctx, h); > + return ret; Again ret doesn't seem needed here. -serge
next prev parent reply other threads:[~2010-03-23 16:09 UTC|newest] Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-03-22 1:06 [C/R ARM][PATCH 0/3] Linux Checkpoint-Restart - ARM port Christoffer Dall 2010-03-22 1:06 ` Christoffer Dall 2010-03-22 1:06 ` [C/R ARM][PATCH 1/3] ARM: Rudimentary syscall interfaces Christoffer Dall 2010-03-22 1:06 ` Christoffer Dall [not found] ` <1269219965-23923-2-git-send-email-christofferdall-77OGu6e99YhyO3AAkE1OcX9LOBIZ5rWg@public.gmane.org> 2010-03-23 20:53 ` Russell King - ARM Linux 2010-03-23 20:53 ` Russell King - ARM Linux 2010-03-23 20:53 ` Russell King - ARM Linux [not found] ` <20100323205342.GA19572-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> 2010-03-24 2:03 ` Matt Helsley 2010-03-24 2:03 ` Matt Helsley 2010-03-24 2:03 ` Matt Helsley [not found] ` <20100324020342.GB5704-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org> 2010-03-24 4:57 ` Oren Laadan 2010-03-24 4:57 ` Oren Laadan 2010-03-24 4:57 ` Oren Laadan [not found] ` <Pine.LNX.4.64.1003240055050.5867-CXF6herHY6ykSYb+qCZC/1i27PF6R63G9nwVQlTi/Pw@public.gmane.org> 2010-03-24 14:02 ` Matt Helsley 2010-03-24 14:02 ` Matt Helsley 2010-03-24 14:02 ` Matt Helsley [not found] ` <20100324140252.GC5704-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org> 2010-03-24 15:53 ` Oren Laadan 2010-03-24 15:53 ` Oren Laadan 2010-03-24 15:53 ` Oren Laadan 2010-03-24 19:36 ` Christoffer Dall 2010-03-24 19:36 ` Christoffer Dall 2010-03-25 1:11 ` Matt Helsley 2010-03-25 1:11 ` Matt Helsley 2010-03-25 1:17 ` Matt Helsley 2010-03-25 1:17 ` Matt Helsley [not found] ` <20100325011753.GF5704-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org> 2010-03-25 10:29 ` Christoffer Dall 2010-03-25 10:29 ` Christoffer Dall 2010-03-25 10:29 ` Christoffer Dall [not found] ` <20100325011132.GE5704-52DBMbEzqgQ/wnmkkaCWp/UQ3DHhIser@public.gmane.org> 2010-03-25 1:17 ` Matt Helsley 2010-03-25 1:35 ` Oren Laadan 2010-03-25 1:35 ` Oren Laadan 2010-03-25 1:35 ` Oren Laadan 2010-03-25 10:34 ` Christoffer Dall 2010-03-25 10:34 ` Christoffer Dall [not found] ` <4BAABDF4.8070904-eQaUEPhvms7ENvBUuze7eA@public.gmane.org> 2010-03-25 10:34 ` Christoffer Dall [not found] ` <7d08b87d1003241236n2b45e6f4ife36da841351df9d-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2010-03-25 1:11 ` Matt Helsley [not found] ` <4BAA3586.1020604-eQaUEPhvms7ENvBUuze7eA@public.gmane.org> 2010-03-24 19:36 ` Christoffer Dall [not found] ` <1269219965-23923-1-git-send-email-christofferdall-77OGu6e99YhyO3AAkE1OcX9LOBIZ5rWg@public.gmane.org> 2010-03-22 1:06 ` Christoffer Dall 2010-03-22 1:06 ` [C/R ARM][PATCH 2/3] ARM: Add the eclone system call Christoffer Dall 2010-03-22 1:06 ` [C/R ARM][PATCH 3/3] c/r: ARM implementation of checkpoint/restart Christoffer Dall 2010-03-22 1:06 ` [C/R ARM][PATCH 2/3] ARM: Add the eclone system call Christoffer Dall 2010-03-22 1:06 ` Christoffer Dall [not found] ` <1269219965-23923-3-git-send-email-christofferdall-77OGu6e99YhyO3AAkE1OcX9LOBIZ5rWg@public.gmane.org> 2010-03-23 21:06 ` Russell King - ARM Linux 2010-03-23 21:06 ` Russell King - ARM Linux 2010-03-23 21:06 ` Russell King - ARM Linux 2010-03-24 18:19 ` Sukadev Bhattiprolu 2010-03-24 18:19 ` Sukadev Bhattiprolu [not found] ` <20100323210616.GB19572-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> 2010-03-24 18:19 ` Sukadev Bhattiprolu 2010-03-24 19:42 ` Christoffer Dall 2010-03-24 19:42 ` Christoffer Dall 2010-03-24 19:42 ` Christoffer Dall 2010-03-22 1:06 ` [C/R ARM][PATCH 3/3] c/r: ARM implementation of checkpoint/restart Christoffer Dall 2010-03-22 1:06 ` Christoffer Dall 2010-03-23 16:09 ` Serge E. Hallyn [this message] 2010-03-23 16:09 ` Serge E. Hallyn 2010-03-24 19:46 ` Christoffer Dall 2010-03-24 19:46 ` Christoffer Dall [not found] ` <20100323160933.GA4465-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> 2010-03-24 19:46 ` Christoffer Dall 2010-03-23 21:18 ` Russell King - ARM Linux 2010-03-23 21:18 ` Russell King - ARM Linux [not found] ` <20100323211843.GC19572-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> 2010-03-24 1:53 ` Matt Helsley 2010-03-24 20:48 ` Christoffer Dall 2010-03-24 1:53 ` Matt Helsley 2010-03-24 1:53 ` Matt Helsley 2010-03-24 20:48 ` Christoffer Dall 2010-03-24 20:48 ` Christoffer Dall [not found] ` <7d08b87d1003241348g347f092k1142318490e0bdcc-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2010-03-26 2:47 ` Jamie Lokier 2010-03-26 2:47 ` Jamie Lokier 2010-03-26 2:47 ` Jamie Lokier [not found] ` <20100326024759.GN19308-yetKDKU6eevNLxjTenLetw@public.gmane.org> 2010-03-26 3:02 ` Paul Mundt 2010-03-26 3:02 ` Paul Mundt 2010-03-26 3:02 ` Paul Mundt 2010-03-26 3:55 ` Jamie Lokier 2010-03-26 3:55 ` Jamie Lokier [not found] ` <20100326030208.GA5815-M7jkjyW5wf5g9hUCZPvPmw@public.gmane.org> 2010-03-26 3:55 ` Jamie Lokier 2010-03-28 22:55 ` Christoffer Dall 2010-03-28 22:55 ` Christoffer Dall 2010-03-28 22:55 ` Christoffer Dall [not found] ` <1269219965-23923-4-git-send-email-christofferdall-77OGu6e99YhyO3AAkE1OcX9LOBIZ5rWg@public.gmane.org> 2010-03-23 16:09 ` Serge E. Hallyn 2010-03-23 21:18 ` Russell King - ARM Linux
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