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2013-08-16Fix TLB gather virtual address range invalidation corner casesLinus Torvalds
Ben Tebulin reported: "Since v3.7.2 on two independent machines a very specific Git repository fails in 9/10 cases on git-fsck due to an SHA1/memory failures. This only occurs on a very specific repository and can be reproduced stably on two independent laptops. Git mailing list ran out of ideas and for me this looks like some very exotic kernel issue" and bisected the failure to the backport of commit 53a59fc67f97 ("mm: limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPT"). That commit itself is not actually buggy, but what it does is to make it much more likely to hit the partial TLB invalidation case, since it introduces a new case in tlb_next_batch() that previously only ever happened when running out of memory. The real bug is that the TLB gather virtual memory range setup is subtly buggered. It was introduced in commit 597e1c3580b7 ("mm/mmu_gather: enable tlb flush range in generic mmu_gather"), and the range handling was already fixed at least once in commit e6c495a96ce0 ("mm: fix the TLB range flushed when __tlb_remove_page() runs out of slots"), but that fix was not complete. The problem with the TLB gather virtual address range is that it isn't set up by the initial tlb_gather_mmu() initialization (which didn't get the TLB range information), but it is set up ad-hoc later by the functions that actually flush the TLB. And so any such case that forgot to update the TLB range entries would potentially miss TLB invalidates. Rather than try to figure out exactly which particular ad-hoc range setup was missing (I personally suspect it's the hugetlb case in zap_huge_pmd(), which didn't have the same logic as zap_pte_range() did), this patch just gets rid of the problem at the source: make the TLB range information available to tlb_gather_mmu(), and initialize it when initializing all the other tlb gather fields. This makes the patch larger, but conceptually much simpler. And the end result is much more understandable; even if you want to play games with partial ranges when invalidating the TLB contents in chunks, now the range information is always there, and anybody who doesn't want to bother with it won't introduce subtle bugs. Ben verified that this fixes his problem. Reported-bisected-and-tested-by: Ben Tebulin <tebulin@googlemail.com> Build-testing-by: Stephen Rothwell <sfr@canb.auug.org.au> Build-testing-by: Richard Weinberger <richard.weinberger@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-06-06arch, mm: Remove tlb_fast_mode()Peter Zijlstra
Since the introduction of preemptible mmu_gather TLB fast mode has been broken. TLB fast mode relies on there being absolutely no concurrency; it frees pages first and invalidates TLBs later. However now we can get concurrency and stuff goes *bang*. This patch removes all tlb_fast_mode() code; it was found the better option vs trying to patch the hole by entangling tlb invalidation with the scheduler. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Reported-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-12x86-32: Fix possible incomplete TLB invalidate with PAE pagetablesDave Hansen
This patch attempts to fix: https://bugzilla.kernel.org/show_bug.cgi?id=56461 The symptom is a crash and messages like this: chrome: Corrupted page table at address 34a03000 *pdpt = 0000000000000000 *pde = 0000000000000000 Bad pagetable: 000f [#1] PREEMPT SMP Ingo guesses this got introduced by commit 611ae8e3f520 ("x86/tlb: enable tlb flush range support for x86") since that code started to free unused pagetables. On x86-32 PAE kernels, that new code has the potential to free an entire PMD page and will clear one of the four page-directory-pointer-table (aka pgd_t entries). The hardware aggressively "caches" these top-level entries and invlpg does not actually affect the CPU's copy. If we clear one we *HAVE* to do a full TLB flush, otherwise we might continue using a freed pmd page. (note, we do this properly on the population side in pud_populate()). This patch tracks whenever we clear one of these entries in the 'struct mmu_gather', and ensures that we follow up with a full tlb flush. BTW, I disassembled and checked that: if (tlb->fullmm == 0) and if (!tlb->fullmm && !tlb->need_flush_all) generate essentially the same code, so there should be zero impact there to the !PAE case. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Artem S Tashkinov <t.artem@mailcity.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04mm: limit mmu_gather batching to fix soft lockups on !CONFIG_PREEMPTMichal Hocko
Since commit e303297e6c3a ("mm: extended batches for generic mmu_gather") we are batching pages to be freed until either tlb_next_batch cannot allocate a new batch or we are done. This works just fine most of the time but we can get in troubles with non-preemptible kernel (CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY) on large machines where too aggressive batching might lead to soft lockups during process exit path (exit_mmap) because there are no scheduling points down the free_pages_and_swap_cache path and so the freeing can take long enough to trigger the soft lockup. The lockup is harmless except when the system is setup to panic on softlockup which is not that unusual. The simplest way to work around this issue is to limit the maximum number of batches in a single mmu_gather. 10k of collected pages should be safe to prevent from soft lockups (we would have 2ms for one) even if they are all freed without an explicit scheduling point. This patch doesn't add any new explicit scheduling points because it relies on zap_pmd_range during page tables zapping which calls cond_resched per PMD. The following lockup has been reported for 3.0 kernel with a huge process (in order of hundreds gigs but I do know any more details). BUG: soft lockup - CPU#56 stuck for 22s! [kernel:31053] Modules linked in: af_packet nfs lockd fscache auth_rpcgss nfs_acl sunrpc mptctl mptbase autofs4 binfmt_misc dm_round_robin dm_multipath bonding cpufreq_conservative cpufreq_userspace cpufreq_powersave pcc_cpufreq mperf microcode fuse loop osst sg sd_mod crc_t10dif st qla2xxx scsi_transport_fc scsi_tgt netxen_nic i7core_edac iTCO_wdt joydev e1000e serio_raw pcspkr edac_core iTCO_vendor_support acpi_power_meter rtc_cmos hpwdt hpilo button container usbhid hid dm_mirror dm_region_hash dm_log linear uhci_hcd ehci_hcd usbcore usb_common scsi_dh_emc scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh dm_snapshot pcnet32 mii edd dm_mod raid1 ext3 mbcache jbd fan thermal processor thermal_sys hwmon cciss scsi_mod Supported: Yes CPU 56 Pid: 31053, comm: kernel Not tainted 3.0.31-0.9-default #1 HP ProLiant DL580 G7 RIP: 0010: _raw_spin_unlock_irqrestore+0x8/0x10 RSP: 0018:ffff883ec1037af0 EFLAGS: 00000206 RAX: 0000000000000e00 RBX: ffffea01a0817e28 RCX: ffff88803ffd9e80 RDX: 0000000000000200 RSI: 0000000000000206 RDI: 0000000000000206 RBP: 0000000000000002 R08: 0000000000000001 R09: ffff887ec724a400 R10: 0000000000000000 R11: dead000000200200 R12: ffffffff8144c26e R13: 0000000000000030 R14: 0000000000000297 R15: 000000000000000e FS: 00007ed834282700(0000) GS:ffff88c03f200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 000000000068b240 CR3: 0000003ec13c5000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kernel (pid: 31053, threadinfo ffff883ec1036000, task ffff883ebd5d4100) Call Trace: release_pages+0xc5/0x260 free_pages_and_swap_cache+0x9d/0xc0 tlb_flush_mmu+0x5c/0x80 tlb_finish_mmu+0xe/0x50 exit_mmap+0xbd/0x120 mmput+0x49/0x120 exit_mm+0x122/0x160 do_exit+0x17a/0x430 do_group_exit+0x3d/0xb0 get_signal_to_deliver+0x247/0x480 do_signal+0x71/0x1b0 do_notify_resume+0x98/0xb0 int_signal+0x12/0x17 DWARF2 unwinder stuck at int_signal+0x12/0x17 Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> [3.0+] Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-27mm/mmu_gather: enable tlb flush range in generic mmu_gatherAlex Shi
This patch enabled the tlb flush range support in generic mmu layer. Most of arch has self tlb flush range support, like ARM/IA64 etc. X86 arch has no this support in hardware yet. But another instruction 'invlpg' can implement this function in some degree. So, enable this feather in generic layer for x86 now. and maybe useful for other archs in further. Generic mmu_gather struct is protected by micro HAVE_GENERIC_MMU_GATHER. Other archs that has flush range supported own self mmu_gather struct. So, now this change is safe for them. In future we may unify this struct and related functions on multiple archs. Thanks for Peter Zijlstra time and time reminder for multiple architecture code safe! Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1340845344-27557-7-git-send-email-alex.shi@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-06-27x86/tlb: add tlb_flushall_shift for specific CPUAlex Shi
Testing show different CPU type(micro architectures and NUMA mode) has different balance points between the TLB flush all and multiple invlpg. And there also has cases the tlb flush change has no any help. This patch give a interface to let x86 vendor developers have a chance to set different shift for different CPU type. like some machine in my hands, balance points is 16 entries on Romely-EP; while it is at 8 entries on Bloomfield NHM-EP; and is 256 on IVB mobile CPU. but on model 15 core2 Xeon using invlpg has nothing help. For untested machine, do a conservative optimization, same as NHM CPU. Signed-off-by: Alex Shi <alex.shi@intel.com> Link: http://lkml.kernel.org/r/1340845344-27557-5-git-send-email-alex.shi@intel.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-01-12thp: add tlb_remove_pmd_tlb_entryShaohua Li
We have tlb_remove_tlb_entry to indicate a pte tlb flush entry should be flushed, but not a corresponding API for pmd entry. This isn't a problem so far because THP is only for x86 currently and tlb_flush() under x86 will flush entire TLB. But this is confusion and could be missed if thp is ported to other arch. Also convert tlb->need_flush = 1 to a VM_BUG_ON(!tlb->need_flush) in __tlb_remove_page() as suggested by Andrea Arcangeli. The __tlb_remove_page() function is supposed to be called after tlb_remove_xxx_tlb_entry() and we can catch any misuse. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm: uninline large generic tlb.h functionsPeter Zijlstra
Some of these functions have grown beyond inline sanity, move them out-of-line. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Requested-by: Andrew Morton <akpm@linux-foundation.org> Requested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm: extended batches for generic mmu_gatherPeter Zijlstra
Instead of using a single batch (the small on-stack, or an allocated page), try and extend the batch every time it runs out and only flush once either the extend fails or we're done. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Requested-by: Nick Piggin <npiggin@kernel.dk> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm, powerpc: move the RCU page-table freeing into generic codePeter Zijlstra
In case other architectures require RCU freed page-tables to implement gup_fast() and software filled hashes and similar things, provide the means to do so by moving the logic into generic code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Requested-by: David Miller <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm: mmu_gather reworkPeter Zijlstra
Rework the existing mmu_gather infrastructure. The direct purpose of these patches was to allow preemptible mmu_gather, but even without that I think these patches provide an improvement to the status quo. The first 9 patches rework the mmu_gather infrastructure. For review purpose I've split them into generic and per-arch patches with the last of those a generic cleanup. The next patch provides generic RCU page-table freeing, and the followup is a patch converting s390 to use this. I've also got 4 patches from DaveM lined up (not included in this series) that uses this to implement gup_fast() for sparc64. Then there is one patch that extends the generic mmu_gather batching. After that follow the mm preemptibility patches, these make part of the mm a lot more preemptible. It converts i_mmap_lock and anon_vma->lock to mutexes which together with the mmu_gather rework makes mmu_gather preemptible as well. Making i_mmap_lock a mutex also enables a clean-up of the truncate code. This also allows for preemptible mmu_notifiers, something that XPMEM I think wants. Furthermore, it removes the new and universially detested unmap_mutex. This patch: Remove the first obstacle towards a fully preemptible mmu_gather. The current scheme assumes mmu_gather is always done with preemption disabled and uses per-cpu storage for the page batches. Change this to try and allocate a page for batching and in case of failure, use a small on-stack array to make some progress. Preemptible mmu_gather is desired in general and usable once i_mmap_lock becomes a mutex. Doing it before the mutex conversion saves us from having to rework the code by moving the mmu_gather bits inside the pte_lock. Also avoid flushing the tlb batches from under the pte lock, this is useful even without the i_mmap_lock conversion as it significantly reduces pte lock hold times. [akpm@linux-foundation.org: fix comment tpyo] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Tony Luck <tony.luck@intel.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Namhyung Kim <namhyung@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-27mm: Pass virtual address to [__]p{te,ud,md}_free_tlb()Benjamin Herrenschmidt
mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() Upcoming paches to support the new 64-bit "BookE" powerpc architecture will need to have the virtual address corresponding to PTE page when freeing it, due to the way the HW table walker works. Basically, the TLB can be loaded with "large" pages that cover the whole virtual space (well, sort-of, half of it actually) represented by a PTE page, and which contain an "indirect" bit indicating that this TLB entry RPN points to an array of PTEs from which the TLB can then create direct entries. Thus, in order to invalidate those when PTE pages are deleted, we need the virtual address to pass to tlbilx or tlbivax instructions. The old trick of sticking it somewhere in the PTE page struct page sucks too much, the address is almost readily available in all call sites and almost everybody implemets these as macros, so we may as well add the argument everywhere. I added it to the pmd and pud variants for consistency. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: David Howells <dhowells@redhat.com> [MN10300 & FRV] Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> [s390] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-04asm-generic/tlb.h: remove <linux/quicklist.h>H. Peter Anvin
Remove unused <linux/quicklist.h> from <asm-generic/tlb.h>; per Christoph Lameter this should have been part of a previous patch reversal but apparently didn't get removed. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-31asm-generic/tlb.h: build fixIngo Molnar
bring back the avr32, blackfin, sh, sparc architectures into working order, by reverting the effects of this change that came in via the x86 tree: commit a5a19c63f4e55e32dc0bc3d936d7f94793d8b380 Author: Jeremy Fitzhardinge <jeremy@goop.org> Date: Wed Jan 30 13:33:39 2008 +0100 x86: demacro asm-x86/pgalloc_32.h Sorry about that! Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-30x86: demacro asm-x86/pgalloc_32.hJeremy Fitzhardinge
Convert macros into inline functions, for better type-checking. This patch required a little bit of fiddling with headers in order to make __(pte|pmd)_free_tlb inline rather than macros. asm-generic/tlb.h includes asm/pgalloc.h, though it doesn't directly use any pgalloc definitions. I removed this include to avoid an include cycle, but it may cause secondary compile failures by things depending on the indirect inclusion; arch/x86/mm/hugetlbpage.c was one such place; there may be others. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-12-26Revert quicklist need->flush fixChristoph Lameter
Did not fix the reported issue. Apart from other weirdness this causes a bad link between the TLB flushing logic and the quicklists. If there is indeed an issue that an arch needs a tlb flush before free then the arch code needs to set tlb->need_flush before calling quicklist_free. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-12-17quicklist: Set tlb->need_flush if pages are remaining in quicklist 0Christoph Lameter
This ensures that the quicklists are drained. Otherwise draining may only occur when the processor reaches an idle state. Fixes fatal leakage of pgd_t's on 2.6.22 and later. Signed-off-by: Christoph Lameter <clameter@sgi.com> Reported-by: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-03fix file specification in commentsUwe Zeisberger
Many files include the filename at the beginning, serveral used a wrong one. Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-26Don't include linux/config.h from anywhere else in include/David Woodhouse
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-10-29[PATCH] mm: tlb_finish_mmu forget rssHugh Dickins
zap_pte_range has been counting the pages it frees in tlb->freed, then tlb_finish_mmu has used that to update the mm's rss. That got stranger when I added anon_rss, yet updated it by a different route; and stranger when rss and anon_rss became mm_counters with special access macros. And it would no longer be viable if we're relying on page_table_lock to stabilize the mm_counter, but calling tlb_finish_mmu outside that lock. Remove the mmu_gather's freed field, let tlb_finish_mmu stick to its own business, just decrement the rss mm_counter in zap_pte_range (yes, there was some point to batching the update, and a subsequent patch restores that). And forget the anal paranoia of first reading the counter to avoid going negative - if rss does go negative, just fix that bug. Remove the mmu_gather's flushes and avoided_flushes from arm and arm26: no use was being made of them. But arm26 alone was actually using the freed, in the way some others use need_flush: give it a need_flush. arm26 seems to prefer spaces to tabs here: respect that. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: tlb_is_full_mm was obscureHugh Dickins
tlb_is_full_mm? What does that mean? The TLB is full? No, it means that the mm's last user has gone and the whole mm is being torn down. And it's an inline function because sparc64 uses a different (slightly better) "tlb_frozen" name for the flag others call "fullmm". And now the ptep_get_and_clear_full macro used in zap_pte_range refers directly to tlb->fullmm, which would be wrong for sparc64. Rather than correct that, I'd prefer to scrap tlb_is_full_mm altogether, and change sparc64 to just use the same poor name as everyone else - is that okay? Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-29[PATCH] mm: tlb_gather_mmu get_cpu_varHugh Dickins
tlb_gather_mmu dates from before kernel preemption was allowed, and uses smp_processor_id or __get_cpu_var to find its per-cpu mmu_gather. That works because it's currently only called after getting page_table_lock, which is not dropped until after the matching tlb_finish_mmu. But don't rely on that, it will soon change: now disable preemption internally by proper get_cpu_var in tlb_gather_mmu, put_cpu_var in tlb_finish_mmu. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-12[PATCH] x86-64: Increase TLB flush array sizeAndi Kleen
The generic TLB flush functions kept upto 506 pages per CPU to avoid too frequent IPIs. This value was done for the L1 cache of older x86 CPUs, but with modern CPUs it does not make much sense anymore. TLB flushing is slow enough that using the L2 cache is fine. This patch increases the flush array on x86-64 to cache 5350 pages. That is roughly 20MB with 4K pages. It speeds up large munmaps in multithreaded processes on SMP considerably. The cost is roughly 42k of memory per CPU, which is reasonable. I only increased it on x86-64 for now, but it would probably make sense to increase it everywhere. Embedded architectures with SMP may keep it smaller to save some memory per CPU. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!