| Message ID | OFB4731A18.0D8D8BC1-ON85256988.0074562B@raleigh.ibm.com |
|---|---|
| State | New, archived |
| Headers | show |
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| Related | show |
On Mon, Oct 30, 2000 at 03:31:22PM -0600, Steve Pratt/Austin/IBM wrote: > [..] no patch ever > appeared. [..] You didn't followed l-k closely enough as the strict fix was submitted two times but it got not merged. (maybe because it had an #ifdef __s390__ that was _necessary_ by that time?) You can find the old and now useless patch here: ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.0-test5/tlb-flush-smp-race-1 Andrea - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
Andrea Arcangeli wrote: > > On Mon, Oct 30, 2000 at 03:31:22PM -0600, Steve Pratt/Austin/IBM wrote: > > [..] no patch ever > > appeared. [..] > > You didn't followed l-k closely enough as the strict fix was submitted two > times but it got not merged. (maybe because it had an #ifdef __s390__ that was > _necessary_ by that time?) > > You can find the old and now useless patch here: > >ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.0-test5/tlb-flush-smp-race-1 I stand corrected, I missed this is my searching. Hopefully this will get in this time. Steve - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
--- linux/mm/memory.c Fri Oct 27 15:26:14 2000 +++ linux-2.4.0-test10patch/mm/memory.c Fri Oct 27 15:45:54 2000 @@ -781,8 +781,8 @@ */ static inline void establish_pte(struct vm_area_struct * vma, unsigned long address, pte_t *page_table, pte_t entry) { - flush_tlb_page(vma, address); set_pte(page_table, entry); + flush_tlb_page(vma, address); update_mmu_cache(vma, address, entry); }
Back in April there were discussions about the race in establish_pte with the flush_tlb before the set_pte. Many options were discussed, but due in part to a concern about S/390 having introduced the code, no patch ever appeared. I talked with Martin Schwidefsky of the S/390 Linux development team and he said that: >the establish_pte was in fact introduced because of Linux/390. We wanted to use the special S/390 instruction ipte (invalidate page >table entry). In the meantime we found out that we need a lot more changes to be able to use this instruction, so we disabled it again. >Until we have a proper patch you should revoke the establish_pte change if you found it to be faulty. I too think there is a race >condition. So while there may be a more elegant solution down the road, I would like to see the simple fix put back into 2.4. Here is the patch to essential put the code back to the way it was before the S/390 merge. Patch is against 2.4.0-test10pre6. Linux Technology Center - IBM Corporation 11400 Burnet Road Austin, TX 78758 (512) 838-9763 EMAIL: SLPratt@US.IBM.COM - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/