Re: cache coherecy when working with cpu dcache write allocate
--- saeed bishara <[EMAIL PROTECTED]> wrote: > Hi, > I came across data corruption problem when using xfs, my system is > arm 926, the data cache is virtually tagged and virtually indexed and > with no hw cache coherency. my CPU features the data cache write > allocate-> when doing store, the cache line of the destination address > is loaded to data cache. > when enabling the write allocate, I got data corruption with the > xfs. the scenario is that the xfs allocates large buffer (for reading > the log records) using vmalloc, and the low level driver (raid) copies > the data to the bio vectors using the linear address, since the write > allocate is enabled, the correct data remains on the data cache with > the linear address tag, when the IO completes, the xfs access the data > with using the vmalloc virtual address, which is different than the > kernel linear address, thus it will get a stale data!. > > how should I fix this problem? I thought that only the > copy/clean_user_pages() functions should be aware to the write > allocate. I wonder if I'm seeing this with reiser4 on pxa27x as well??? Steve ___ Now you can have your favourite RSS headlines come to you with the all new Yahoo! Mail. http://uk.docs.yahoo.com/nowyoucan.html - 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/
cache coherecy when working with cpu dcache write allocate
Hi, I came across data corruption problem when using xfs, my system is arm 926, the data cache is virtually tagged and virtually indexed and with no hw cache coherency. my CPU features the data cache write allocate-> when doing store, the cache line of the destination address is loaded to data cache. when enabling the write allocate, I got data corruption with the xfs. the scenario is that the xfs allocates large buffer (for reading the log records) using vmalloc, and the low level driver (raid) copies the data to the bio vectors using the linear address, since the write allocate is enabled, the correct data remains on the data cache with the linear address tag, when the IO completes, the xfs access the data with using the vmalloc virtual address, which is different than the kernel linear address, thus it will get a stale data!. how should I fix this problem? I thought that only the copy/clean_user_pages() functions should be aware to the write allocate. saeed - 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/
cache coherecy when working with cpu dcache write allocate
Hi, I came across data corruption problem when using xfs, my system is arm 926, the data cache is virtually tagged and virtually indexed and with no hw cache coherency. my CPU features the data cache write allocate- when doing store, the cache line of the destination address is loaded to data cache. when enabling the write allocate, I got data corruption with the xfs. the scenario is that the xfs allocates large buffer (for reading the log records) using vmalloc, and the low level driver (raid) copies the data to the bio vectors using the linear address, since the write allocate is enabled, the correct data remains on the data cache with the linear address tag, when the IO completes, the xfs access the data with using the vmalloc virtual address, which is different than the kernel linear address, thus it will get a stale data!. how should I fix this problem? I thought that only the copy/clean_user_pages() functions should be aware to the write allocate. saeed - 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/
Re: cache coherecy when working with cpu dcache write allocate
--- saeed bishara [EMAIL PROTECTED] wrote: Hi, I came across data corruption problem when using xfs, my system is arm 926, the data cache is virtually tagged and virtually indexed and with no hw cache coherency. my CPU features the data cache write allocate- when doing store, the cache line of the destination address is loaded to data cache. when enabling the write allocate, I got data corruption with the xfs. the scenario is that the xfs allocates large buffer (for reading the log records) using vmalloc, and the low level driver (raid) copies the data to the bio vectors using the linear address, since the write allocate is enabled, the correct data remains on the data cache with the linear address tag, when the IO completes, the xfs access the data with using the vmalloc virtual address, which is different than the kernel linear address, thus it will get a stale data!. how should I fix this problem? I thought that only the copy/clean_user_pages() functions should be aware to the write allocate. I wonder if I'm seeing this with reiser4 on pxa27x as well??? Steve ___ Now you can have your favourite RSS headlines come to you with the all new Yahoo! Mail. http://uk.docs.yahoo.com/nowyoucan.html - 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/
