Re: Disc cache worth it?
In article , Tim Powys-Lybbe wrote: > > Rather than hijack this mailing list, you'd be welcome to post these > > questions to the ROOL bounty forum: > > > > https://www.riscosopen.org/forum/forums/8 > Can't stand forums. Rather than attempt to get Tim to grapple with his personal demons, I have taken the liberty of posting his suggestions myself so that they might reach a better target audience. Didn't take long, as he'd already done most of the necessary typing! John -- | John Williams | joh...@ukgateway.net Names for Soul Band:- Soul Beneficiary *
Re: Disc cache worth it?
On 25 Jun at 15:22, "Steve (plusnet)" wrote: > On 2014-06-25 14:57, Tim Powys-Lybbe wrote: > > I have intermittently subscribed to a bounty or two. > > Rather than hijack this mailing list, you'd be welcome to post these > questions to the ROOL bounty forum: > > https://www.riscosopen.org/forum/forums/8 Can't stand forums. Too much hassle to find the site and the discussion. Mailing lists and usenet are so much easier: the discussion just appears on MessengerPro. I take it that you are not interested in following up your comments on bounties, to which I was merely replying? -- Tim Powys-Lybbe t...@powys.org for a miscellany of bygones: http://powys.org/
Re: Disc cache worth it?
On 2014-06-25 14:57, Tim Powys-Lybbe wrote: I have intermittently subscribed to a bounty or two. Rather than hijack this mailing list, you'd be welcome to post these questions to the ROOL bounty forum: https://www.riscosopen.org/forum/forums/8 Cheers, Steve
Re: Disc cache worth it?
On 25 Jun at 13:32, "Steve (plusnet)" wrote: > It is hoped that one of the later stages of "filesystem improvements" > that we've been hosting bounties about on the ROOL site will address > some of these issues, but at the current rate that the bounty scheme > has been gathering donations, we'll all be dead and gone before any of > that work happens. I have intermittently subscribed to a bounty or two. I wonder if the ROOL systems could improve the volume of subscriptions received: 1. By issuing a public report occasionally (yearly? And to csaa?) on what has been achieved and what could do with more funding. 2. When a Bounty has been fulfilled, write to the subscribers to tell them of this good news and invite them to subscribe to other bounties instead, even including with this a list of priorities for RISC OS. 3. Consider changing some aspects of ROOL to a charity, certainly including the Bounty aspect. This would enable the trustees to reclaim income tax paid by the bounty donors. Further the donors who pay higher rate tax could deduct their subscription from the higher rate income, thereby reducing their higher rate tax; if they felt so minded they could then increase their donation by the amount of this higher rate tax relief. That said, how much do you think is needed in the relevant bounty (which?) to encourage a developer to start work? -- Tim Powys-Lybbe t...@powys.org for a miscellany of bygones: http://powys.org/
Re: Disc cache worth it?
On 2014-06-25 13:51, Rob Kendrick wrote: Of course not :) But from the user's point of view, everything does stop :) Pesky users... :) Steve
Re: Disc cache worth it?
On Wed, Jun 25, 2014 at 01:44:01PM +0100, Steve (plusnet) wrote: > On 2014-06-25 13:36, Rob Kendrick wrote: > >(Getting into the technical distinctions between WIMP and non-WIMP > >tasks > >was something I was trying to avoid getting into on the user's > >mailing > >list :) > > Fair enough, but if you're going to say things like "the whole system > stops while the individual chunks are written" and "Under RISC OS, > file system writes stop /everthing/ until they complete" you can't > expect > me to just sit by and say nothing... Of course not :) But from the user's point of view, everything does stop :) B.
Re: Disc cache worth it?
On 2014-06-25 13:36, Rob Kendrick wrote: (Getting into the technical distinctions between WIMP and non-WIMP tasks was something I was trying to avoid getting into on the user's mailing list :) Fair enough, but if you're going to say things like "the whole system stops while the individual chunks are written" and "Under RISC OS, file system writes stop /everthing/ until they complete" you can't expect me to just sit by and say nothing... ;) Steve
Re: Disc cache worth it?
On Wed, Jun 25, 2014 at 01:32:58PM +0100, Steve (plusnet) wrote: > Secondly, it's not true to say file system operations block everything > in RISC OS - some file systems (notably ADFS) implement "background > transfers" which allow much of RISC OS to continue to operate while the > underlying file operation runs (e.g. via DMA or some such). However, > many > file systems _don't_ implement background transfers - e.g. SDFS - so > these will hog the system for the duration of the low-level operation. But even with background transfers, the Wimp will typically not continue, no? My understanding is that OS_File SWIs that write data only return when the data is written, and thus the application cannot call Wimp_Poll to allow multitasking to continue - and even if you're using UnixLib threads this doesn't help you because threading does not continue over such SWIs. (Getting into the technical distinctions between WIMP and non-WIMP tasks was something I was trying to avoid getting into on the user's mailing list :) B.
Re: Disc cache worth it?
On 2014-06-25 12:57, Rob Kendrick wrote: On Wed, Jun 25, 2014 at 12:14:16PM +0100, george greenfield wrote: Does that mean that selecting 'Make file operations multitask' in !Configure-Filer, actually doesn't? It means that it writes smaller chunks and calls Wimp_Poll in between them to give other applications a chance, at the expense of expediency. The whole system stops while the individual chunks are written, being accepted by FileSwitch, which then in turn passes them to the handling file system (most likely FileCore), which then hands them to the block device driver (ADFS, IDEFS, SDFS, etc), percolating the success/failure result back up the stack to the application. I think there are a couple of errors in that explanation. First of all, IIRC ticking that option only affects FilerAction. This is a desktop facility for doing multitasking operations on files and directories (such as copy, move, delete, etc) with a window opening to show progress. Unticking that option causes these operations to revert to using the single-tasking command line equivalents for these operations (e.g. *copy) which could end up being faster at the expense that your desktop stops multitasking. Secondly, it's not true to say file system operations block everything in RISC OS - some file systems (notably ADFS) implement "background transfers" which allow much of RISC OS to continue to operate while the underlying file operation runs (e.g. via DMA or some such). However, many file systems _don't_ implement background transfers - e.g. SDFS - so these will hog the system for the duration of the low-level operation. Adding background transfers to SDFS has always been on the roadmap but it's a lot of work; implementing background transfers on RISC OS is a particularly tricky task and SDFS is complex enough already for various reasons. It is hoped that one of the later stages of "filesystem improvements" that we've been hosting bounties about on the ROOL site will address some of these issues, but at the current rate that the bounty scheme has been gathering donations, we'll all be dead and gone before any of that work happens. Ta, Steve
Re: Disc cache worth it?
On Wed, Jun 25, 2014 at 12:14:16PM +0100, george greenfield wrote: > In message <20140624211245.gm1...@platypus.pepperfish.net> > Rob Kendrick wrote: > > > On Tue, Jun 24, 2014 at 06:36:18PM +0100, Chris Young wrote: > >> > >> It would be interesting to see if a Raspberry Pi running the GTK > >> version from SD card has the same slowness. > > > > Assuming you were running it on one of the flavours of UNIX available > > for it (Linux, NetBSD), then no. > > > > These operating systems receive the write requests from applications and > > queue them for writing to underlying block devices in the background, > > while other apps sit there waiting for input or idling. Under RISC OS, > > file system writes stop /everthing/ until they complete. > > Does that mean that selecting 'Make file operations multitask' in > !Configure-Filer, actually doesn't? It means that it writes smaller chunks and calls Wimp_Poll in between them to give other applications a chance, at the expense of expediency. The whole system stops while the individual chunks are written, being accepted by FileSwitch, which then in turn passes them to the handling file system (most likely FileCore), which then hands them to the block device driver (ADFS, IDEFS, SDFS, etc), percolating the success/failure result back up the stack to the application. On other operating systems (UNIX, Windows, BeOS, AmigaOS, OS X), the equivalent of FileSwitch passes the request onto the file system which then writes the data through a buffering system and thus can return almost straight away, while a background process in the kernel then flushes the buffer to the block device while the system is not busy, or a timeout expires. During this process, reads are satisfied through the buffer because they've not yet reached the block device. There is some functionality in Vince's disc cache work to allow for something similar to the "file operations multitask" option, and may need tuning. As he said, this is an experimental feature and the feedback that has been happening does have some value. B.
Re: Disc cache worth it?
In message <20140624211245.gm1...@platypus.pepperfish.net> Rob Kendrick wrote: > On Tue, Jun 24, 2014 at 06:36:18PM +0100, Chris Young wrote: >> >> It would be interesting to see if a Raspberry Pi running the GTK >> version from SD card has the same slowness. > > Assuming you were running it on one of the flavours of UNIX available > for it (Linux, NetBSD), then no. > > These operating systems receive the write requests from applications and > queue them for writing to underlying block devices in the background, > while other apps sit there waiting for input or idling. Under RISC OS, > file system writes stop /everthing/ until they complete. > [snip] Does that mean that selecting 'Make file operations multitask' in !Configure-Filer, actually doesn't? -- George
Re: Disc cache worth it?
On Tue, Jun 24, 2014 at 06:36:18PM +0100, Chris Young wrote: > > It would be interesting to see if a Raspberry Pi running the GTK > version from SD card has the same slowness. Assuming you were running it on one of the flavours of UNIX available for it (Linux, NetBSD), then no. These operating systems receive the write requests from applications and queue them for writing to underlying block devices in the background, while other apps sit there waiting for input or idling. Under RISC OS, file system writes stop /everthing/ until they complete. (Under UNIX, applications should call the fdatasync() function when the data stored to disc is in a consistent/useful state, which guarentees the data has reached backing store, but then they also have pre-emptive multitasking so you can still use your computer when this happens.) B.
Re: Disc cache worth it?
On 24 Jun 2014 Vincent Sanders wrote: > Although this reply is to Peter it applies to all the subsequent > discussion. > Firstly, as I did memntion in my original mail this feature is new and > not tuned yet so may have adverse behaviour on some systems. Please do > not draw any conclusions about the usefulness or otherwise of this > feature from *development* snapshots. > If you want stable behaviour the 3.1 release should be used. It may > well turn out that this feature is simply unsuitable for RISC OS but > we are at the beginning of a long road. > As we have seen with the issues around !Cache and now with general > perfomance, the challenges of building a cache suitable for use across > many systems are not inconsiderable [snip very interesting bits, but a lot of which goes right over my head!] > In summary, the cache: > - Is still in development. > - Is not a panacea and will not benefit everyone. > - Is a compromise trade, and it seems for some systems with slow disc >it is literally faster to retrieve from network than from local >storage. > - Is likely to be very large to be effective as the source web pages >are large. > - Can be disabled by setting its size to zero. > I will look into adding a heuristic to disable or at least tune the > cache writeout if it detects it is exceeding the available disc > bandwidth. Many thanks for this, and I did realise that it's still rather a test feature and a compromise, but I just wondered whether I was doing things right, and I'm glad I am. I'm also glad the my logfile was of interest. I'll stick with it (like many people of my age, I find I get more patient as I get older), and will await developments with interest. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
Re: Disc cache worth it?
On Tue, 24 Jun 2014 15:20:55 +0100, Vincent Sanders wrote: > Because the code does not moderate its write rate you have to watch > the hourglass as it saves those files to disc. This is made much > worse, as as I understand it from knowlageable RISC OS people, because > disc writes are not performed in the background. Same problem on AmigaOS I think, although as I'm using a proper HDD the delay is negligible (and the disk cache makes a noticeable difference). > In your example if we assume you managed to get four megabytes of > cached data to be written and it took 30 seconds to achive that, we > get a write rate of around 130K/second or roughly a Megabit/second. > Your network connection does not have to be very good at all to outrun > the disc and hence the disc cache is making a horrible trade in your > case. Remember that write speeds on SD cards are significantly slower than read speeds, and lots of small writes are slower still. It would be interesting to see if a Raspberry Pi running the GTK version from SD card has the same slowness. Chris
Re: Disc cache worth it?
Although this reply is to Peter it applies to all the subsequent discussion. Firstly, as I did memntion in my original mail this feature is new and not tuned yet so may have adverse behaviour on some systems. Please do not draw any conclusions about the usefulness or otherwise of this feature from *development* snapshots. If you want stable behaviour the 3.1 release should be used. It may well turn out that this feature is simply unsuitable for RISC OS but we are at the beginning of a long road. As we have seen with the issues around !Cache and now with general perfomance, the challenges of building a cache suitable for use across many systems are not inconsiderable On Mon, Jun 23, 2014 at 05:58:52PM +0100, Peter Young wrote: > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to > have found some downsides to it, and I wonder if (a) I'm doing it > correctly and (b) if it's worth the occasional faster opening of some > sites. Subsequent mails indicate you were using this correctly, as to the "worth it" that is what we need to evaluate. I prevoiusly mentioned it, but I shall re-iterate: The persistant cache is purely a trade, in this case it is trading disc resource for network resources. I use the term disc resource carefully, it includes both storage space *and* the time to store and retrieve the files. Similarly network resource is the data downloaded *and* the latency getting that data. > > If I load, for instance, http://www.bbc.co.uk/news/ as the first site > of a session, it loads maybe a little faster, but then I get > intermittent hourglass activity for sometimes up to thirty seconds, > during which I can't do anything else. There are several other sites, > for instance Wikipedia home page, which do the same. And the next day > the same happens. What is happening here is that when your browser has gone idle after retrieving the website you have numerous objects (images html files etc.) which are eligible to be written out to the persistent cache. Given the front page of the BBC news site is (right now) 1.1 Megabytes in 187 files which can rise to in the region of 2 Megabytes or more if there are a image heavy news stories, that represents a great deal of data to be written out. The write out task then starts writing these to disc limited by a bandwidth cap. In the current implementation this is hard wired to a maximum write bandwidth of 512K/second. It had not occurred to me that such a rate would not be achievable. Because the code does not moderate its write rate you have to watch the hourglass as it saves those files to disc. This is made much worse, as as I understand it from knowlageable RISC OS people, because disc writes are not performed in the background. In your example if we assume you managed to get four megabytes of cached data to be written and it took 30 seconds to achive that, we get a write rate of around 130K/second or roughly a Megabit/second. Your network connection does not have to be very good at all to outrun the disc and hence the disc cache is making a horrible trade in your case. > > Looking in !Cache, which is in !Boot.!Resources, I find that in the > Caches.Default.NetSurf directory there are currently 1933 files, > totalling 22449384 bytes. Is this to be expected, as I don't use > NetSurf a huge amount? I've already excluded this directory from my > daily backup, which has been taking a lot longer since I started using > !Cache. The web is huge these days, 22 Megabytes is literally only 20 pages on most sites, even if the site shares those objects between multiple pages, just visiting all the heading sections of BBC news requires 10Megabytes of persistant storage and over 1000 files. For example google chrome by default uses 16Megabyte blocks to store sub 16k sized objects and creates four of those to start with It is not uncommon for a well used browser to have several gigabytes of disc used for web caches. In most current systems using a gigabyte of RAM let alone Disc is not uncommon. In summary, the cache: - Is still in development. - Is not a panacea and will not benefit everyone. - Is a compromise trade, and it seems for some systems with slow disc it is literally faster to retrieve from network than from local storage. - Is likely to be very large to be effective as the source web pages are large. - Can be disabled by setting its size to zero. I will look into adding a heuristic to disable or at least tune the cache writeout if it detects it is exceeding the available disc bandwidth. -- Regards Vincent http://www.kyllikki.org/
Re: Disc cache worth it?
In article , David Pitt wrote: > Peter Young, on 23 Jun, wrote: > > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to > > have found some downsides to it, and I wonder if (a) I'm doing it > > correctly and (b) if it's worth the occasional faster opening of some > > sites. > > [snip] > Overall I was not persuaded that the cache results is any meaningful > speed up and could even slow things up, not just on the Raspberry Pi but > also on the Iyonix and VRPC on a Windows 7 laptop with an SSD. It's all a bit technical for me and I just tried it to see what might happen on a Windows 7 VRPC machine that is fitted with a Crucial Adrenaline SSD cache. I am, thus far, not getting problems and it fairly motors. Might the SSD cache have any relevance? [snip] > I have uninstalled !Cache. It's staying where it is on this machine for now.
Re: Disc cache worth it?
Tony Moore, on 24 Jun, wrote: > On 24 Jun 2014, David Pitt wrote: > > [snip] > > > !Cache on a RamDisc looks much more promising. This is much better, the > > improvement is clear, and the machine is not taken over as the cache is > > written. > > NetSurf already has a Memory Cache. For the Disc Cache to serve any useful > purpose, it needs to be written to a non-volatile medium. Indeed. I do agree, I was just testing something. -- David Pitt
Re: Disc cache worth it?
On 24 Jun 2014, David Pitt wrote: [snip] > !Cache on a RamDisc looks much more promising. This is much better, > the improvement is clear, and the machine is not taken over as the > cache is written. NetSurf already has a Memory Cache. For the Disc Cache to serve any useful purpose, it needs to be written to a non-volatile medium. Tony
Re: Disc cache worth it?
Daniel Silverstone, on 24 Jun, wrote: > On Tue, Jun 24, 2014 at 08:10:29 +0100, David Pitt wrote: > > !Cache on a RamDisc looks much more promising. This is much better, the > > improvement is clear, and the machine is not taken over as the cache is > > written. > > You do realise that this is more work for the computer to do than simply > increasing the maximum size of the RAM cache in the browser? I had not got that far. The notion was just to highlight where the blockage is. In practice the two options perform similarly, as very briefly tested. -- David Pitt
Re: Disc cache worth it?
On Tue, Jun 24, 2014 at 08:10:29 +0100, David Pitt wrote: > !Cache on a RamDisc looks much more promising. This is much better, the > improvement is clear, and the machine is not taken over as the cache is > written. You do realise that this is more work for the computer to do than simply increasing the maximum size of the RAM cache in the browser? D. -- Daniel Silverstone http://www.netsurf-browser.org/ PGP mail accepted and encouraged.Key Id: 3CCE BABE 206C 3B69
Re: Disc cache worth it?
On 23 Jun 2014 "Chris Young" wrote: > On Mon, 23 Jun 2014 22:43:52 +0100, Peter Young wrote: Thanks, Chris. I've a couple of busy days coming up, with one early start, but I'll try to save a log after a new day's start-up, and give some timings of the hourglass activity on the BBC news site. Where or to whom should I post the log? >> >>> The best thing to do is raise a bug report and attach it to that. >> >> OK, but is it really a bug? I'll do as you suggest, anyway. > If it's not working as it should, it's a bug. :) > There may be something that can be done to improve matters, such as > delaying disk cache writes until the browser isn't busy, or only > writing out when the item is removed from the memory cache. It may be > that it is a true bug and is writing when it shouldn't be, or there is > some performance problem which is nothing to do with disk I/O. Bug report submitted, with this mornings timings, and the logfile. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
Re: Disc cache worth it?
Rob Kendrick, on 23 Jun, wrote: [snip] > > Overall I was not persuaded that the cache results is any meaningful > > speed up and could even slow things up, not just on the Raspberry Pi but > > also on the Iyonix and VRPC on a Windows 7 laptop with an SSD. > > Certainly on UNIX and BeOS, it seems to provide a significant performance > boost, but this is probably because of their far superior IO layers. !Cache on a RamDisc confirms that. -- David Pitt
Re: Disc cache worth it?
Malcolm Hussain-Gambles, on 23 Jun, wrote: > Just for a positive, I have a panda board my Internet connection is > 120mbit. I do notice a difference. The Panda is going to be faster than a Raspberry Pi. > From my understanding and benchmarks the sd card can write at 20MB/sec > and the fastest tcp I can get is 6MB/sec read and that's off a local > webserver for testing purposes. > So I can't see how it would be slower to be honest. I'm slightly confused. As I understand it the small file write speed even on supposedly fast SD cards can be very slow. This certainly seems to be the case on the Pi. It first became really apparent after a particularly long winded !PackMan installation. A large number of small files is a problem. External drives are better but are only USB1. !Cache on a RamDisc looks much more promising. This is much better, the improvement is clear, and the machine is not taken over as the cache is written. -- David Pitt
Re: Disc cache worth it?
On 23 Jun 2014, Rob Kendrick wrote: [snip] > On RISC OS, the disc cache *may* only be a win for people on slow > connections. Using RISC OS on a RiscPC, with a slow internet connection, and Cache enabled, I found that launching half a dozen stories from Google News caused the machine to be virtually unusable for half an hour, or more. Judging by the hard-drive activity light, Cache writes to disc on the fly. However, if it were to postpone writing until NetSurf was quit, the delay would occur then. Either way, inconvenient. Tony
Re: Disc cache worth it?
On Mon, 23 Jun 2014 22:43:52 +0100, Peter Young wrote: > >> Thanks, Chris. I've a couple of busy days coming up, with one early > >> start, but I'll try to save a log after a new day's start-up, and give > >> some timings of the hourglass activity on the BBC news site. Where or > >> to whom should I post the log? > > > The best thing to do is raise a bug report and attach it to that. > > OK, but is it really a bug? I'll do as you suggest, anyway. If it's not working as it should, it's a bug. :) There may be something that can be done to improve matters, such as delaying disk cache writes until the browser isn't busy, or only writing out when the item is removed from the memory cache. It may be that it is a true bug and is writing when it shouldn't be, or there is some performance problem which is nothing to do with disk I/O. Chris
Re: Disc cache worth it?
Perhaps having scrap and cache is causing issues on the same card? I use memphis for scrap? On 23 Jun 2014, Rob Kendrick wrote: >On Mon, Jun 23, 2014 at 07:04:53PM +0100, David Pitt wrote: >> Peter Young, on 23 Jun, wrote: >> >> > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem >to have >> > found some downsides to it, and I wonder if (a) I'm doing it >correctly and >> > (b) if it's worth the occasional faster opening of some sites. >> > >> > If I load, for instance, http://www.bbc.co.uk/news/ as the first >site of a >> > session, it loads maybe a little faster, but then I get >intermittent >> > hourglass activity for sometimes up to thirty seconds, during which >I >> > can't do anything else. There are several other sites, for instance >> > Wikipedia home page, which do the same. And the next day the same >happens. >> >> I have found much the same, a really good example of this is the >Daily >> Mail's heavy weight site. > >Ultimately, my advice is to not visit this service. This stands >regardless of any cache issues that may exist :) > >> http://www.dailymail.co.uk/home/index.html >> >> Writes to the Raspberry Pi's SD Card are so slow that !Cache is not >going to >> be good news on it. It is better with !Cache on a Fat32 harddisc >connected >> to the Pi and on the Iyonix but is still an issue. > >Indeed, SD has poor write performance almost anywhere, like most >flash-based devices. > >> Overall I was not persuaded that the cache results is any meaningful >speed >> up and could even slow things up, not just on the Raspberry Pi but >also on >> the Iyonix and VRPC on a Windows 7 laptop with an SSD. > >Certainly on UNIX and BeOS, it seems to provide a significant >performance boost, but this is probably because of their far superior >IO >layers. > >On RISC OS, the disc cache *may* only be a win for people on slow >connections. > >B. -- Sent with K-@ Mail - the evolution of emailing.
Re: Disc cache worth it?
Just for a positive, I have a panda board my Internet connection is 120mbit. I do notice a difference. >From my understanding and benchmarks the sd card can write at 20MB/sec and the >fastest tcp I can get is 6MB/sec read and that's off a local webserver for >testing purposes. So I can't see how it would be slower to be honest. I'm slightly confused. Cheers, Malcolm On 23 Jun 2014, Rob Kendrick wrote: >On Mon, Jun 23, 2014 at 07:04:53PM +0100, David Pitt wrote: >> Peter Young, on 23 Jun, wrote: >> >> > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem >to have >> > found some downsides to it, and I wonder if (a) I'm doing it >correctly and >> > (b) if it's worth the occasional faster opening of some sites. >> > >> > If I load, for instance, http://www.bbc.co.uk/news/ as the first >site of a >> > session, it loads maybe a little faster, but then I get >intermittent >> > hourglass activity for sometimes up to thirty seconds, during which >I >> > can't do anything else. There are several other sites, for instance >> > Wikipedia home page, which do the same. And the next day the same >happens. >> >> I have found much the same, a really good example of this is the >Daily >> Mail's heavy weight site. > >Ultimately, my advice is to not visit this service. This stands >regardless of any cache issues that may exist :) > >> http://www.dailymail.co.uk/home/index.html >> >> Writes to the Raspberry Pi's SD Card are so slow that !Cache is not >going to >> be good news on it. It is better with !Cache on a Fat32 harddisc >connected >> to the Pi and on the Iyonix but is still an issue. > >Indeed, SD has poor write performance almost anywhere, like most >flash-based devices. > >> Overall I was not persuaded that the cache results is any meaningful >speed >> up and could even slow things up, not just on the Raspberry Pi but >also on >> the Iyonix and VRPC on a Windows 7 laptop with an SSD. > >Certainly on UNIX and BeOS, it seems to provide a significant >performance boost, but this is probably because of their far superior >IO >layers. > >On RISC OS, the disc cache *may* only be a win for people on slow >connections. > >B. -- Sent with K-@ Mail - the evolution of emailing.
Re: Disc cache worth it?
On Mon, Jun 23, 2014 at 07:04:53PM +0100, David Pitt wrote: > Peter Young, on 23 Jun, wrote: > > > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to have > > found some downsides to it, and I wonder if (a) I'm doing it correctly and > > (b) if it's worth the occasional faster opening of some sites. > > > > If I load, for instance, http://www.bbc.co.uk/news/ as the first site of a > > session, it loads maybe a little faster, but then I get intermittent > > hourglass activity for sometimes up to thirty seconds, during which I > > can't do anything else. There are several other sites, for instance > > Wikipedia home page, which do the same. And the next day the same happens. > > I have found much the same, a really good example of this is the Daily > Mail's heavy weight site. Ultimately, my advice is to not visit this service. This stands regardless of any cache issues that may exist :) > http://www.dailymail.co.uk/home/index.html > > Writes to the Raspberry Pi's SD Card are so slow that !Cache is not going to > be good news on it. It is better with !Cache on a Fat32 harddisc connected > to the Pi and on the Iyonix but is still an issue. Indeed, SD has poor write performance almost anywhere, like most flash-based devices. > Overall I was not persuaded that the cache results is any meaningful speed > up and could even slow things up, not just on the Raspberry Pi but also on > the Iyonix and VRPC on a Windows 7 laptop with an SSD. Certainly on UNIX and BeOS, it seems to provide a significant performance boost, but this is probably because of their far superior IO layers. On RISC OS, the disc cache *may* only be a win for people on slow connections. B.
Re: Disc cache worth it?
On 23 Jun 2014 "Chris Young" wrote: > On Mon, 23 Jun 2014 21:13:17 +0100, Peter Young wrote: >> Thanks, Chris. I've a couple of busy days coming up, with one early >> start, but I'll try to save a log after a new day's start-up, and give >> some timings of the hourglass activity on the BBC news site. Where or >> to whom should I post the log? > The best thing to do is raise a bug report and attach it to that. OK, but is it really a bug? I'll do as you suggest, anyway. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
Re: Disc cache worth it?
On Mon, 23 Jun 2014 21:13:17 +0100, Peter Young wrote: > Thanks, Chris. I've a couple of busy days coming up, with one early > start, but I'll try to save a log after a new day's start-up, and give > some timings of the hourglass activity on the BBC news site. Where or > to whom should I post the log? The best thing to do is raise a bug report and attach it to that. Chris
Re: Disc cache worth it?
On 23 Jun 2014 David Pitt wrote: > Peter Young, on 23 Jun, wrote: >> I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to have >> found some downsides to it, and I wonder if (a) I'm doing it correctly and >> (b) if it's worth the occasional faster opening of some sites. >> >> If I load, for instance, http://www.bbc.co.uk/news/ as the first site of a >> session, it loads maybe a little faster, but then I get intermittent >> hourglass activity for sometimes up to thirty seconds, during which I >> can't do anything else. There are several other sites, for instance >> Wikipedia home page, which do the same. And the next day the same happens. > I have found much the same, a really good example of this is the Daily > Mail's heavy weight site. > http://www.dailymail.co.uk/home/index.html > Writes to the Raspberry Pi's SD Card are so slow that !Cache is not going to > be good news on it. It is better with !Cache on a Fat32 harddisc connected > to the Pi and on the Iyonix but is still an issue. > Overall I was not persuaded that the cache results is any meaningful speed > up and could even slow things up, not just on the Raspberry Pi but also on > the Iyonix and VRPC on a Windows 7 laptop with an SSD. Thanks, David, and I'm glad it's not just me. I'll await what Chris makes of a logfile, when I get a round tuit, and will maybe then uninstall !Cache. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
Re: Disc cache worth it?
On 23 Jun 2014 "Chris Young" wrote: > On Mon, 23 Jun 2014 17:58:52 +0100, Peter Young wrote: >> If I load, for instance, http://www.bbc.co.uk/news/ as the first site >> of a session, it loads maybe a little faster, but then I get >> intermittent hourglass activity for sometimes up to thirty seconds, >> during which I can't do anything else. There are several other sites, >> for instance Wikipedia home page, which do the same. And the next day >> the same happens. > I'm sure Vince will correct me here, but I believe NetSurf saves the > cache files to disk when they are downloaded (as opposed to when they > are evicted from the memory cache), so you will get a delay as NetSurf > gets busy saving the files. > If you've gone back to the same site though most of the files should > be loading from disk and I wouldn't expect any additional delay. You > will need to post a log file so we can get a handle on exactly what is > causing the pauses. Thanks, Chris. I've a couple of busy days coming up, with one early start, but I'll try to save a log after a new day's start-up, and give some timings of the hourglass activity on the BBC news site. Where or to whom should I post the log? >> Looking in !Cache, which is in !Boot.!Resources, I find that in the >> Caches.Default.NetSurf directory there are currently 1933 files, >> totalling 22449384 bytes. Is this to be expected, as I don't use >> NetSurf a huge amount? > Yes. That's only 22MB. The default limit is 1GB. >> I've already excluded this directory from my >> daily backup, which has been taking a lot longer since I started using >> !Cache. > There's no point in backing up these files. Thanks again for these two points. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
Re: Disc cache worth it?
Peter Young, on 23 Jun, wrote: > I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to have > found some downsides to it, and I wonder if (a) I'm doing it correctly and > (b) if it's worth the occasional faster opening of some sites. > > If I load, for instance, http://www.bbc.co.uk/news/ as the first site of a > session, it loads maybe a little faster, but then I get intermittent > hourglass activity for sometimes up to thirty seconds, during which I > can't do anything else. There are several other sites, for instance > Wikipedia home page, which do the same. And the next day the same happens. I have found much the same, a really good example of this is the Daily Mail's heavy weight site. http://www.dailymail.co.uk/home/index.html Writes to the Raspberry Pi's SD Card are so slow that !Cache is not going to be good news on it. It is better with !Cache on a Fat32 harddisc connected to the Pi and on the Iyonix but is still an issue. Overall I was not persuaded that the cache results is any meaningful speed up and could even slow things up, not just on the Raspberry Pi but also on the Iyonix and VRPC on a Windows 7 laptop with an SSD. > Looking in !Cache, which is in !Boot.!Resources, I find that in the > Caches.Default.NetSurf directory there are currently 1933 files, totalling > 22449384 bytes. Is this to be expected, as I don't use NetSurf a huge > amount? I've already excluded this directory from my daily backup, which > has been taking a lot longer since I started using !Cache. A lot of stuff is cached and the default maximum cache size is 1GB. It's not worth backing up, it's transient data that expires in a default of 28 days. I have uninstalled !Cache. -- David Pitt
Re: Disc cache worth it?
On Mon, 23 Jun 2014 17:58:52 +0100, Peter Young wrote: > If I load, for instance, http://www.bbc.co.uk/news/ as the first site > of a session, it loads maybe a little faster, but then I get > intermittent hourglass activity for sometimes up to thirty seconds, > during which I can't do anything else. There are several other sites, > for instance Wikipedia home page, which do the same. And the next day > the same happens. I'm sure Vince will correct me here, but I believe NetSurf saves the cache files to disk when they are downloaded (as opposed to when they are evicted from the memory cache), so you will get a delay as NetSurf gets busy saving the files. If you've gone back to the same site though most of the files should be loading from disk and I wouldn't expect any additional delay. You will need to post a log file so we can get a handle on exactly what is causing the pauses. > Looking in !Cache, which is in !Boot.!Resources, I find that in the > Caches.Default.NetSurf directory there are currently 1933 files, > totalling 22449384 bytes. Is this to be expected, as I don't use > NetSurf a huge amount? Yes. That's only 22MB. The default limit is 1GB. > I've already excluded this directory from my > daily backup, which has been taking a lot longer since I started using > !Cache. There's no point in backing up these files. Chris
Disc cache worth it?
I've been using the disc cache on RISC OS 2.19, ARMini, and I seem to have found some downsides to it, and I wonder if (a) I'm doing it correctly and (b) if it's worth the occasional faster opening of some sites. If I load, for instance, http://www.bbc.co.uk/news/ as the first site of a session, it loads maybe a little faster, but then I get intermittent hourglass activity for sometimes up to thirty seconds, during which I can't do anything else. There are several other sites, for instance Wikipedia home page, which do the same. And the next day the same happens. Looking in !Cache, which is in !Boot.!Resources, I find that in the Caches.Default.NetSurf directory there are currently 1933 files, totalling 22449384 bytes. Is this to be expected, as I don't use NetSurf a huge amount? I've already excluded this directory from my daily backup, which has been taking a lot longer since I started using !Cache. Best wishes, Peter. -- Peter Young (zfc W) and family Prestbury, Cheltenham, Glos. GL52, England http://pnyoung.orpheusweb.co.uk pnyo...@ormail.co.uk
