Hi! On Fri, 2 Aug 2013 11:37:26 -0400, Johannes Weiner wrote: > Each zone that holds userspace pages of one workload must be aged at a > speed proportional to the zone size. [...] > Fix this with a very simple round robin allocator. [...] This patch, adding NR_ALLOC_BATCH, eventually landed in mainline as commit 81c0a2bb515fd4daae8cab64352877480792b515 (2013-09-11). I recently upgraded a Debian testing system from a 3.11 kernel to 3.12, and it started to exhibit "strange" issues, which I then bisected to this patch. I'm not saying that the patch is faulty, as it seems to be working fine for everyone else, so I rather assume that something in a (vastly?) different corner of the kernel (or my hardware?) is broken. ;-) The issue is that when X.org/lightdm starts up, there are "garbled" section on the screen, for example, rectangular boxes that are just black or otherwise "distorted", and/or sets of glyphs (corresponding to a set of characters; but not all characters) are displayed as rectangular gray or black boxes, and/or icons in a GNOME session are not displayed properly, and so on. (Can take a snapshot if that helps?) Switching to a Linux console, I can use that one fine. Switching back to X, in the majority of all cases, the screen will be completely black, but with the mouse cursor still rendered properly (done in hardware, I assume). Reverting commit 81c0a2bb515fd4daae8cab64352877480792b515, for example on top of v3.12, and everything is back to normal. The problem also persists with a v3.14 kernel that I just built. I will try to figure out what's going on, but will gladly take any pointers, or suggestions about how to tackle such a problem. The hardware is a Fujitsu Siemens Esprimo E5600, mainboard D2264-A1, CPU AMD Sempron 3000+. There is a on-board graphics thingy, but I'm not using that; instead I put in a Sapphire Radeon HD 4350 card. $ cat < /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 15 model : 47 model name : AMD Sempron(tm) Processor 3000+ stepping : 2 cpu MHz : 1000.000 cache size : 128 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt lm 3dnowext 3dnow rep_good nopl pni lahf_lm bogomips : 2000.20 TLB size : 1024 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: ts fid vid ttp tm stc $ sudo lspci -nn -k -vv 00:00.0 Host bridge [0600]: Silicon Integrated Systems [SiS] 761/M761 Host [1039:0761] (rev 01) Subsystem: Fujitsu Technology Solutions D2030-A1 Motherboard [1734:1099] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- SERR- Capabilities: [d0] HyperTransport: Slave or Primary Interface Command: BaseUnitID=0 UnitCnt=17 MastHost- DefDir- DUL- Link Control 0: CFlE- CST- CFE- TAbort- SERR- TAbort- Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [d0] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0 ExtTag+ RBE- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq+ AuxPwr+ TransPend- LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <1us, L1 <2us ClockPM- Surprise- LLActRep+ BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk+ ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive+ BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- Slot #0, PowerLimit 75.000W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg- Control: AttnInd Off, PwrInd Off, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState- RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [bc] HyperTransport: MSI Mapping Enable- Fixed+ Capabilities: [a0] MSI: Enable- Count=1/1 Maskable- 64bit- Address: 00000000 Data: 0000 Capabilities: [f4] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Kernel driver in use: pcieport 00:02.0 ISA bridge [0601]: Silicon Integrated Systems [SiS] SiS965 [MuTIOL Media IO] [1039:0965] (rev 48) Control: I/O+ Mem+ BusMaster+ SpecCycle+ MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx- Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- Reset- FastB2B- PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn- Capabilities: [b0] Subsystem: Silicon Integrated Systems [SiS] Device [1039:0000] Capabilities: [c0] MSI: Enable+ Count=1/1 Maskable- 64bit- Address: fee0100c Data: 4181 Capabilities: [d0] Express (v1) Root Port (Slot+), MSI 00 DevCap: MaxPayload 128 bytes, PhantFunc 0 ExtTag+ RBE- DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported- RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+ MaxPayload 128 bytes, MaxReadReq 128 bytes DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr+ TransPend- LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Exit Latency L0s <1us, L1 <2us ClockPM- Surprise- LLActRep- BwNot- LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- CommClk- ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt- LnkSta: Speed 2.5GT/s, Width x0, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt- SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- Slot #0, PowerLimit 0.000W; Interlock- NoCompl- SltCtl: Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg- Control: AttnInd Off, PwrInd Off, Power- Interlock- SltSta: Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet+ Interlock- Changed: MRL- PresDet- LinkState- RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible- RootCap: CRSVisible- RootSta: PME ReqID 0000, PMEStatus- PMEPending- Capabilities: [f4] Power Management version 2 Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Capabilities: [100 v1] Virtual Channel Caps: LPEVC=0 RefClk=100ns PATEntryBits=1 Arb: Fixed- WRR32- WRR64- WRR128- Ctrl: ArbSelect=Fixed Status: InProgress- VC0: Caps: PATOffset=00 MaxTimeSlots=1 RejSnoopTrans- Arb: Fixed- WRR32- WRR64- WRR128- TWRR128- WRR256- Ctrl: Enable+ ID=0 ArbSelect=Fixed TC/VC=ff Status: NegoPending- InProgress- Capabilities: [130 v1] Advanced Error Reporting UESta: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UEMsk: DLP- SDES- TLP- FCP- CmpltTO- CmpltAbrt- UnxCmplt- RxOF- MalfTLP- ECRC- UnsupReq- ACSViol- UESvrt: DLP+ SDES- TLP- FCP+ CmpltTO- CmpltAbrt- UnxCmplt- RxOF+ MalfTLP+ ECRC- UnsupReq- ACSViol- CESta: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr- CEMsk: RxErr- BadTLP- BadDLLP- Rollover- Timeout- NonFatalErr- AERCap: First Error Pointer: 00, GenCap- CGenEn- ChkCap- ChkEn- Kernel driver in use: pcieport 00:09.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8169 PCI Gigabit Ethernet Controller [10ec:8169] (rev 10) Subsystem: Fujitsu Technology Solutions D2030-A1 [1734:1091] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV+ VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- TAbort- SERR- Kernel driver in use: radeon 01:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] RV710/730 HDMI Audio [Radeon HD 4000 series] [1002:aa38] Subsystem: PC Partner Limited / Sapphire Technology Device [174b:aa38] Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- Kernel driver in use: snd_hda_intel Grüße, Thomas