Re: [Crash-utility] [PATCH] add -s option to vm to display one vma at a time

----- Original Message ----- > At 2012-3-13 17:56, qiaonuohan wrote: > > Hello Dave, > > When I am using "vm -p" command, I feel it is chaotic when too > much data is printed. I think it is clear to display one vma > each time. > > In the patch, I compare all vmas with the argument of -s option. > If an equal vma is found, it will be printed like below. > > crash> vm -ps ffff88028ff7d3a0 > VMA START END FLAGS FILE > ffff88028ff7d3a0 7fff29b71000 7fff29b87000 100173 > VIRTUAL PHYSICAL > 7fff29b71000 (not mapped) > 7fff29b72000 (not mapped) > 7fff29b73000 (not mapped) > 7fff29b74000 (not mapped) > 7fff29b75000 (not mapped) > 7fff29b76000 (not mapped) > 7fff29b77000 27faad000 > 7fff29b78000 2807aa000 > 7fff29b79000 280781000 > 7fff29b7a000 280787000 > 7fff29b7b000 280776000 > 7fff29b7c000 280786000 > 7fff29b7d000 27f2df000 > 7fff29b7e000 27f2e0000 > 7fff29b7f000 27f2e1000 > 7fff29b80000 27f2d7000 > 7fff29b81000 28b1ac000 > 7fff29b82000 28ecc1000 > 7fff29b83000 28c5c2000 > 7fff29b84000 28aaf4000 > 7fff29b85000 28aaf9000 > 7fff29b86000 289566000 > crash> Seems like a reasonable request. However, I don't like your mixing it with the "-R reference" usage, because it confuses things like this simple example: crash> vm -p -s ffff810ec9f57818 VMA START END FLAGS FILE ffff810ec9f57818 4010d000 40110000 101877 /usr/local/java/jdk1.5.0_19/bin/java VIRTUAL PHYSICAL 4010d000 ec89b1000 4010e000 FILE: /usr/local/java/jdk1.5.0_19/bin/java OFFSET: e000 4010f000 e99803000 crash> If the command above were to be qualified with a "-R 4010e000" reference check, it results in a nonsensical error message: crash> vm -p -s ffff810ec9f57818 -R 4010e000 vm: only one -R option allowed Usage: vm [-p | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ... Enter "help vm" for details. crash> A few suggestions: (1) Don't even bother to tie it in with the "vm -v" option, because if you already know the vm_area_struct address, then just print it with "vm_area_struct<address>". (2) Then, since it *only* applies with the -p functionality, make it a new "-P<vmaddr>" option, where the help page explains that the <vmaddr> argument must be a vm_area_struct of the current context: Usage: vm [-p | -P vmaddr | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ... (3) Make -P mutually exclusive with all of the other options. (4) Do not use the reference structure for this feature. Just use your new flag, and pass the vma address in the 3rd "vaddr" argument to vm_area_dump(), since it's not even being used by cmd_vm().

Dave -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility