* Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] @ 2004-08-16 22:56 Yasunori Goto 2004-08-16 23:35 ` Dave Hansen 0 siblings, 1 reply; 6+ messages in thread From: Yasunori Goto @ 2004-08-16 22:56 UTC (permalink / raw) To: linux-kernel, linux-mm; +Cc: mbligh Hello. I made new patches for Memory hotplug. Dave Hansen-san recommeded me I should forward these to LKML or linux-mm. So, I'll forword these. Please comment. Thanks. Forwarded by Yasunori Goto <ygoto@us.fujitsu.com> ----------------------- Original Message ----------------------- From: Yasunori Goto <ygoto@us.fujitsu.com> To: lhms-devel@lists.sourceforge.net Date: Mon, 16 Aug 2004 14:35:29 -0700 Subject: [Lhms-devel] Making hotremovable attribute with memory section[0/4] ---- Hello. Previous hot-removable attribute in my patches was only for node. I made new patches to create hot-removable attribute for memory section. This patches are for patch-2.6.8-rc4-mm1-mhp3. (This is in http://sprucegoose.sr71.net/patches/) Please comment. Thanks. -- Yasunori Goto <ygoto at us.fujitsu.com> ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ Lhms-devel mailing list Lhms-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lhms-devel --------------------- Original Message Ends -------------------- -- Yasunori Goto <ygoto at us.fujitsu.com> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] 2004-08-16 22:56 Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] Yasunori Goto @ 2004-08-16 23:35 ` Dave Hansen 2004-08-17 0:27 ` Alan Cox 0 siblings, 1 reply; 6+ messages in thread From: Dave Hansen @ 2004-08-16 23:35 UTC (permalink / raw) To: Yasunori Goto; +Cc: Linux Kernel Mailing List, linux-mm, Martin J. Bligh On Mon, 2004-08-16 at 15:56, Yasunori Goto wrote: > I made new patches for Memory hotplug. > Dave Hansen-san recommeded me I should forward these to LKML > or linux-mm. > So, I'll forword these. I think I suggested that you forward _one_ ;) In any case, the question of the day is, does anyone have any suggestions on how to create 2 separate pools for pages: one representing hot-removable pages, and the other pages that may not be removed? Yasunori's patch takes the approach of creating a new free_area struct inside each zone. Another approach might be to actually create new 'struct zones' for the new areas. The new zones one seems cleaner to me, but the implementation might end up rippling in to a lot of different areas of code. -- Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] 2004-08-16 23:35 ` Dave Hansen @ 2004-08-17 0:27 ` Alan Cox 2004-08-17 5:15 ` Yasunori Goto 2004-08-17 7:52 ` Fw: " Dave Hansen 0 siblings, 2 replies; 6+ messages in thread From: Alan Cox @ 2004-08-17 0:27 UTC (permalink / raw) To: Dave Hansen Cc: Yasunori Goto, Linux Kernel Mailing List, linux-mm, Martin J. Bligh On Maw, 2004-08-17 at 00:35, Dave Hansen wrote: > In any case, the question of the day is, does anyone have any > suggestions on how to create 2 separate pools for pages: one > representing hot-removable pages, and the other pages that may not be > removed? How do you define the split. There are lots of circumstances where user pages can be pinned for a long (near indefinite) period of time and used for DMA. Consider - Video capture - AGP Gart - AGP based framebuffer (intel i8/9xx) - O_DIRECT I/O There are also things like cluster interconnects, sendfile and the like involved here. Alan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Lhms-devel] Making hotremovable attribute with memory section[0/4] 2004-08-17 0:27 ` Alan Cox @ 2004-08-17 5:15 ` Yasunori Goto 2004-08-17 9:58 ` Dave Jones 2004-08-17 7:52 ` Fw: " Dave Hansen 1 sibling, 1 reply; 6+ messages in thread From: Yasunori Goto @ 2004-08-17 5:15 UTC (permalink / raw) To: Alan Cox Cc: Dave Hansen, Linux Kernel Mailing List, linux-mm, Martin J. Bligh Hello. > On Maw, 2004-08-17 at 00:35, Dave Hansen wrote: > > In any case, the question of the day is, does anyone have any > > suggestions on how to create 2 separate pools for pages: one > > representing hot-removable pages, and the other pages that may not be > > removed? > > How do you define the split. There are lots of circumstances where user > pages can be pinned for a long (near indefinite) period of time and used > for DMA. Basically, kernel have to wait of completion of I/O. > Consider > - Video capture > - AGP Gart > - AGP based framebuffer (intel i8/9xx) I didn't consider deeply about this, because usually enterprise server doesn't need Video capture feature or AGP. It is usually controlled from other machine. If it is really necessary, kernel might have to wait I/O completion or driver modification is necessary. > - O_DIRECT I/O I can use page remmaping method by Iwamoto-san. (See: http://people.valinux.co.jp/~iwamoto/mh.html#remap) I guess that many case can be saved by this. > There are also things like cluster interconnects, sendfile and the like > involved here. In sendfile case, kernel will wait too. Sooner or later, it will be timeout. Thank you for your comment. Bye. -- Yasunori Goto <ygoto at us.fujitsu.com> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Lhms-devel] Making hotremovable attribute with memory section[0/4] 2004-08-17 5:15 ` Yasunori Goto @ 2004-08-17 9:58 ` Dave Jones 0 siblings, 0 replies; 6+ messages in thread From: Dave Jones @ 2004-08-17 9:58 UTC (permalink / raw) To: Yasunori Goto Cc: Alan Cox, Dave Hansen, Linux Kernel Mailing List, linux-mm, Martin J. Bligh On Mon, Aug 16, 2004 at 10:15:51PM -0700, Yasunori Goto wrote: > > Consider > > - Video capture > > - AGP Gart > > - AGP based framebuffer (intel i8/9xx) > > I didn't consider deeply about this, because usually > enterprise server doesn't need Video capture feature or AGP. AMD64's IOMMU is implemented using the AGP GART. This feature is certainly used in server environments. Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] 2004-08-17 0:27 ` Alan Cox 2004-08-17 5:15 ` Yasunori Goto @ 2004-08-17 7:52 ` Dave Hansen 1 sibling, 0 replies; 6+ messages in thread From: Dave Hansen @ 2004-08-17 7:52 UTC (permalink / raw) To: Alan Cox Cc: Yasunori Goto, Linux Kernel Mailing List, linux-mm, Martin J. Bligh On Mon, 2004-08-16 at 17:27, Alan Cox wrote: > On Maw, 2004-08-17 at 00:35, Dave Hansen wrote: > > In any case, the question of the day is, does anyone have any > > suggestions on how to create 2 separate pools for pages: one > > representing hot-removable pages, and the other pages that may not be > > removed? > > How do you define the split. We would hope not to have to define the split explicitly. Since we're hotplugging memory and resizing zones anyway, it shouldn't be a real functional problem to balance memory between the 2 states, no matter how it is implemented. > There are lots of circumstances where user > pages can be pinned for a long (near indefinite) period of time and used > for DMA. For simple cases, anything tricky like DMA will simply be in an unremovable area. However, some platforms like ppc64 logical partitions, require firmware notification of DMA areas. The ppc64 firmware provides consistent remapping functionality for these DMA areas if they ever need to be hot-swapped. > Consider > - Video capture > - AGP Gart > - AGP based framebuffer (intel i8/9xx) > - O_DIRECT I/O > > There are also things like cluster interconnects, sendfile and the like > involved here. When we get to trying to forcefully migrate the kinds of memory that you reference above, we'll likely need firmware support like ppc64 has. The other option is to have some driver callbacks to tell them to reallocate their buffers into new areas, if that's even possible. But, even that's not something I see ever happening to the entire tree, more likely a small subset of the drivers that really need it. -- Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a> ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2004-08-17 9:58 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2004-08-16 22:56 Fw: [Lhms-devel] Making hotremovable attribute with memory section[0/4] Yasunori Goto 2004-08-16 23:35 ` Dave Hansen 2004-08-17 0:27 ` Alan Cox 2004-08-17 5:15 ` Yasunori Goto 2004-08-17 9:58 ` Dave Jones 2004-08-17 7:52 ` Fw: " Dave Hansen
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