From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nitin Gupta Date: Fri, 31 Mar 2017 02:46:47 +0000 Subject: Re: tlb_batch_add_one() Message-Id: <4942fe75-29a0-5b26-c72c-452436d148d4@oracle.com> List-Id: References: <20170328.175226.210187301635964014.davem@davemloft.net> In-Reply-To: <20170328.175226.210187301635964014.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On 3/30/17 5:42 PM, Nitin Gupta wrote: > On 3/30/17 4:59 PM, Nitin Gupta wrote: >> On 3/30/17 2:54 PM, David Miller wrote: >>> From: David Miller >>> Date: Thu, 30 Mar 2017 14:25:53 -0700 (PDT) >>> >>>> From: Nitin Gupta >>>> Date: Thu, 30 Mar 2017 13:47:11 -0700 >>>> >>>>> I will be sending a fix for these call-sites today. >>>> >>>> I already have a fix I'm testing now which I'll check in after my >>>> regression test passes. >>> >>> So even with the shifts fixed, as per the patch below, I'm still getting >>> corruptions during gcc bootstraps. >>> >>> If I cannot figure out what the problem is by the end of the day I'm >>> reverting the change. I've already spend a week trying to figure out >>> what introduced these regressions... >>> >>> diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c >>> index afda3bb..ee8066c 100644 >>> --- a/arch/sparc/mm/tlb.c >>> +++ b/arch/sparc/mm/tlb.c >>> @@ -154,7 +154,7 @@ static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr, >>> if (pte_val(*pte) & _PAGE_VALID) { >>> bool exec = pte_exec(*pte); >>> >>> - tlb_batch_add_one(mm, vaddr, exec, false); >>> + tlb_batch_add_one(mm, vaddr, exec, PAGE_SHIFT); >>> } >>> pte++; >>> vaddr += PAGE_SIZE; >>> @@ -209,9 +209,9 @@ void set_pmd_at(struct mm_struct *mm, unsigned long addr, >>> pte_t orig_pte = __pte(pmd_val(orig)); >>> bool exec = pte_exec(orig_pte); >>> >>> - tlb_batch_add_one(mm, addr, exec, true); >>> + tlb_batch_add_one(mm, addr, exec, REAL_HPAGE_SHIFT); >>> tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec, >>> - true); >>> + REAL_HPAGE_SHIFT); >> >> >> Shifts are still wrong: tlb_batch_add_one -> flush_tsb_user_page expects >> HPAGE_SHIFT to be passed for 8M pages so that 'HUGE' tsb is flushed >> instead of the BASE one. So, we need to pass HPAGE_SHIFT here. >> >> Also, I see that sun4v_tte_to_shift() should return HPAGE_SHIFT for 4MB >> case instead of REAL_HPAGE_SHIFT (same for sun4u version). >> >> And finally, huge_tte_to_shift() can have the size check removed after >> fixing huge_tte_to_shift() as above. >> >> Currently my test machine is having some disk issues, so I will be back >> with results once the machine is back up. >> > > Or more simply, the check in flush_tsb_user() and flush_tsb_user_page() > can be fixed. Below is the full patch (including your changes): > > The patch is untested and my test machine is still not ready, so would > be testing it tonight/tomorrow. > > > Tested with 'make -j64' for kernel: Without it, build fails at 'LD vmlinux.o' step (internal error - probably due to memory corruption). With patch, build succeeds. Nitin