[reiserfs-list] Re: [reiserfs-dev] Re: Note describing poor dcache utilization under high memory pressure
Josh MacDonald <[EMAIL PROTECTED]> said: [...] > We're not talking about actively referenced entries, we're talking about > entries on the d_lru list with zero references. Relocating those objects > should not require any more locking than currently required to remove and > re-insert the dcache entry. Right? If they are unreferenced, they can be dropped without much cost. The problem is what to do if you have 40 pages, each 1/10 filled with data in active use. -- Horst von Brand http://counter.li.org # 22616 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[reiserfs-list] Re: [reiserfs-dev] Re: Note describing poor dcache utilization under high memory pressure
Oliver Xymoron wrote: > >Can we get you to agree that basically all subpage objects are immovable? > No. Certainly not in the general case, and I think Josh found ways to handle the dcache case. If we can simply free the old objects, we don't actually have to move the hot ones, as he points out. > >And as a consequence that garbage collecting at subpage levels doesn't >guarantee freeing up any pages that can then be given up to other >subsystems in response to VM pressure? The GC must think in terms of pages >to actually make progress. > >One of the design goals of slab by the way is that objects of a similar >type will end up having similar lifetimes, avoiding some of the worst >cases of sub-page allocations. > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[reiserfs-list] Re: [reiserfs-dev] Re: Note describing poor dcache utilization under high memory pressure
Oliver Xymoron wrote: Can we get you to agree that basically all subpage objects are immovable? No. Certainly not in the general case, and I think Josh found ways to handle the dcache case. If we can simply free the old objects, we don't actually have to move the hot ones, as he points out. And as a consequence that garbage collecting at subpage levels doesn't guarantee freeing up any pages that can then be given up to other subsystems in response to VM pressure? The GC must think in terms of pages to actually make progress. One of the design goals of slab by the way is that objects of a similar type will end up having similar lifetimes, avoiding some of the worst cases of sub-page allocations. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[reiserfs-list] Re: [reiserfs-dev] Re: Note describing poor dcache utilization under high memory pressure
Josh MacDonald [EMAIL PROTECTED] said: [...] We're not talking about actively referenced entries, we're talking about entries on the d_lru list with zero references. Relocating those objects should not require any more locking than currently required to remove and re-insert the dcache entry. Right? If they are unreferenced, they can be dropped without much cost. The problem is what to do if you have 40 pages, each 1/10 filled with data in active use. -- Horst von Brand http://counter.li.org # 22616 - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
