On Fri, 8 Mar 2013 18:59:15 +0100 Oleg Nesterov <[email protected]> wrote:
> Change dump_write(), dump_seek() and do_coredump() to check > signal_pending() and abort if it is true. hm, why. I think we're missing some context here - this is to support freezing, yes? There's some undescribed interaction between the freezer and the core-dumper which is being fixed? IOW, can we please have the high-level overview of what this patchset is trying to achieve? An example of why this is needed: the dump_interrupted() check which was added to dump_seek() is just weird. An lseek is instantaneous, so why do we need to bother checking for signals there if the caller will be checking one microsecond later anyway?? And if the file doesn't support lseek (do such files exist? should we be returning 0 instead of -ENOMEM?), we just sit there in a loop extending the file with write(). This can take *ages*, but this part of dump_seek() *didn't* get the signal check! So it makes no sense at all. If we had that what-Oleg-is-trying-to-do text then perhaps others could understand all of this? > We add the new trivial helper, dump_interrupted(), to document that > this probably needs more work and to simplify the potential freezer > changes. Perhaps it will have more callers. > > Ideally it should do try_to_freeze() but then we need the unpleasant > changes in dump_write() and wait_for_dump_helpers(). So far we simply > accept the fact that the freezer can truncate a core-dump but at least > you can reliably suspend. OK, so there is some connection between this and suspending. Details, please... -- 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/
