search for: 32kbytes

hi all, the stacksize required for encoder and decoder are 32Kbytes and 16 Kbyes respectively. i changed it to 20Kbytess and 8Kbytes and it seems to work. but need to trim further. can someone point me in the right direction to further reducing the stack size? thanks! cheers, tk

...-------------------------------- Suggestion to address all above comments: 1. allocate a bunch of pages and link them up, calculating the min and the max pfn. if max-min exceeds the allocated bitmap size, tell host. 2. limit allocated bitmap size to something reasonable. How about 32Kbytes? This is 256kilo bit in the map, which comes out to 1Giga bytes of memory in the balloon. ------------------------------------------------------------------------------------- Because the PFNs of the allocated pages are not linear increased, so 3 transmissions are impossible. Liang > &g...

...-------------------------------- Suggestion to address all above comments: 1. allocate a bunch of pages and link them up, calculating the min and the max pfn. if max-min exceeds the allocated bitmap size, tell host. 2. limit allocated bitmap size to something reasonable. How about 32Kbytes? This is 256kilo bit in the map, which comes out to 1Giga bytes of memory in the balloon. ------------------------------------------------------------------------------------- Because the PFNs of the allocated pages are not linear increased, so 3 transmissions are impossible. Liang > &g...

...a transmission: 1 the call count of madvise: 42 Maybe the result will be worse if the guest is not idle, or the guest has more RAM. Do you want more data? Is it worth to do that? Liang > > > > > 2. limit allocated bitmap size to something reasonable. > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > out to 1Giga bytes of memory in the balloon. > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > memory. > > Maybe it's better to use a big page bitmap the save the pages > > alloc...

...a transmission: 1 the call count of madvise: 42 Maybe the result will be worse if the guest is not idle, or the guest has more RAM. Do you want more data? Is it worth to do that? Liang > > > > > 2. limit allocated bitmap size to something reasonable. > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > out to 1Giga bytes of memory in the balloon. > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > memory. > > Maybe it's better to use a big page bitmap the save the pages > > alloc...

...t; Suggestion to address all above comments: > 1. allocate a bunch of pages and link them up, > calculating the min and the max pfn. > if max-min exceeds the allocated bitmap size, > tell host. > 2. limit allocated bitmap size to something reasonable. > How about 32Kbytes? This is 256kilo bit in the map, which comes > out to 1Giga bytes of memory in the balloon. > ------------------------------------------------------------------------------------- > Because the PFNs of the allocated pages are not linear increased, so 3 transmissions > are impossibl...

...bove comments: > > 1. allocate a bunch of pages and link them up, > > calculating the min and the max pfn. > > if max-min exceeds the allocated bitmap size, > > tell host. > > 2. limit allocated bitmap size to something reasonable. > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > out to 1Giga bytes of memory in the balloon. > > ---------------------------------------------------------------------- > > --------------- Because the PFNs of the allocated pages are not linear > > increased, so 3 transmi...

...bove comments: > > 1. allocate a bunch of pages and link them up, > > calculating the min and the max pfn. > > if max-min exceeds the allocated bitmap size, > > tell host. > > 2. limit allocated bitmap size to something reasonable. > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > out to 1Giga bytes of memory in the balloon. > > ---------------------------------------------------------------------- > > --------------- Because the PFNs of the allocated pages are not linear > > increased, so 3 transmi...

..._bmap_hdr); > + vb->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, GFP_KERNEL); So it can go up to 1MByte but adding header size etc you need a higher order allocation. This is a waste, there is no need to have a power of two allocation. Start from the other side. Say "I want to allocate 32KBytes for the bitmap". Subtract the header and you get bitmap size. Calculate the pfn limit from there. > + > + /* Clear the feature bit if memory allocation fails */ > + if (!vb->bmap_hdr) > + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP); > + else > + vb->page_...

..._bmap_hdr); > + vb->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, GFP_KERNEL); So it can go up to 1MByte but adding header size etc you need a higher order allocation. This is a waste, there is no need to have a power of two allocation. Start from the other side. Say "I want to allocate 32KBytes for the bitmap". Subtract the header and you get bitmap size. Calculate the pfn limit from there. > + > + /* Clear the feature bit if memory allocation fails */ > + if (!vb->bmap_hdr) > + __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_BITMAP); > + else > + vb->page_...

...on and it's bad for > > performance improvement. Right? > > It's a tradeoff for sure. Measure it, see what the overhead is. OK, I will try and get back to you. > > > > > > 2. limit allocated bitmap size to something reasonable. > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > out to 1Giga bytes of memory in the balloon. > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > memory. > > Maybe it's better to use a big page bitmap the save the pages > > alloc...

...on and it's bad for > > performance improvement. Right? > > It's a tradeoff for sure. Measure it, see what the overhead is. OK, I will try and get back to you. > > > > > > 2. limit allocated bitmap size to something reasonable. > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > out to 1Giga bytes of memory in the balloon. > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > memory. > > Maybe it's better to use a big page bitmap the save the pages > > alloc...

...e, or the guest has more RAM. > Do you want more data? > > Is it worth to do that? > > Liang Either my math is wrong or there's an implementation bug. > > > > > > > 2. limit allocated bitmap size to something reasonable. > > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > > out to 1Giga bytes of memory in the balloon. > > > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > > memory. > > > Maybe it's better to use a big page bitmap the save...

...s just a simple NAT and a redirect to Squid to force transparent cache so the user does not have to configure his browser. The Problem: ========== I did not do any shaping, even on squid no shaping, and all i get using the NETSPEED GNOME plugin on the Internet side is 16 Kbytes per sec up and 32Kbytes/sec on the Local side as total speed of the whole 3 networks. and as you should have noticed, my Linux box should work as a water hause or pipe and has no real effect on the bandwidth. if i returned back the windows ISA box the speed goes normally at its 52kbyte/sec. so what is happening FOR...

..., e.g. The allocated pages are across a wide range and the max-min > limit is very frequently to be true. Then, there will be many times of virtio transmission and it's bad for performance improvement. Right? > 2. limit allocated bitmap size to something reasonable. > How about 32Kbytes? This is 256kilo bit in the map, which comes > out to 1Giga bytes of memory in the balloon. So, even the VM has 1TB of RAM, the page bitmap will take 32MB of memory. Maybe it's better to use a big page bitmap the save the pages allocated by balloon, and split the big page bitmap to 32K...

..., e.g. The allocated pages are across a wide range and the max-min > limit is very frequently to be true. Then, there will be many times of virtio transmission and it's bad for performance improvement. Right? > 2. limit allocated bitmap size to something reasonable. > How about 32Kbytes? This is 256kilo bit in the map, which comes > out to 1Giga bytes of memory in the balloon. So, even the VM has 1TB of RAM, the page bitmap will take 32MB of memory. Maybe it's better to use a big page bitmap the save the pages allocated by balloon, and split the big page bitmap to 32K...

...b->bmap_hdr = kzalloc(hdr_len + vb->bmap_len, GFP_KERNEL); > > So it can go up to 1MByte but adding header size etc you need a higher order > allocation. This is a waste, there is no need to have a power of two allocation. > Start from the other side. Say "I want to allocate 32KBytes for the bitmap". > Subtract the header and you get bitmap size. > Calculate the pfn limit from there. > Indeed, will change. Thanks a lot! Liang

How well suited is btrfs to low-end and high-end FLASH devices? Paraphrasing from a thread elsewhere: FLASH can be categorised into two classes, which have extremely different characteristics: (a) the low-end (USB, SDHC, CF, cheap ATA SSD); and (b) the high-end (SAS, PCIe, NAS, expensive ATA SSD). My own experience is that the low end (a) can have erase blocks as large as 4MBytes or more

...1. allocate a bunch of pages and link them up, > > > calculating the min and the max pfn. > > > if max-min exceeds the allocated bitmap size, > > > tell host. > > > 2. limit allocated bitmap size to something reasonable. > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > out to 1Giga bytes of memory in the balloon. > > > ---------------------------------------------------------------------- > > > --------------- Because the PFNs of the allocated pages are not linear > > > inc...

...improvement. Right? > > > > It's a tradeoff for sure. Measure it, see what the overhead is. > > OK, I will try and get back to you. > > > > > > > > > > 2. limit allocated bitmap size to something reasonable. > > > > How about 32Kbytes? This is 256kilo bit in the map, which comes > > > > out to 1Giga bytes of memory in the balloon. > > > > > > So, even the VM has 1TB of RAM, the page bitmap will take 32MB of > > memory. > > > Maybe it's better to use a big page bitmap the save...